McQuay MPS015F Installation Manual

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Installation and Maintenance Manual IM 1058

Maverick™ II Commercial Packaged Rooftop Systems

Heating & Cooling Models MPS015F – 050F 15 to 50 Tons R-410A Refrigerant

MicroTech

III Unit Controller

Group: Applied Systems

Part Number: IM 1058

Date: January 2010

Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

General Information. . . . . . . . . . . . . . . . . . . . . . . . 3

Unit Nameplate . . . . . . . . . . . . . . . . . . . . . . . . . 3

Hazard Identification Information . . . . . . . . . . . . 3

Nomenclature (MPS 015–050) . . . . . . . . . . . . . 3

Mechanical Installation . . . . . . . . . . . . . . . . . . . . . . 4

Installer Responsibilities . . . . . . . . . . . . . . . . . . . . 4

Receiving Inspection . . . . . . . . . . . . . . . . . . . . . 4

Service Clearance . . . . . . . . . . . . . . . . . . . . . . . 4

Ventilation Clearance. . . . . . . . . . . . . . . . . . . . . 5

Overhead Clearance . . . . . . . . . . . . . . . . . . . . . 5

Roof Curb Assembly and Installation. . . . . . . . . 5

Rigging and Handling . . . . . . . . . . . . . . . . . . . 10

Additional Weights for Motors/Exhaust Fans. . 11 Additional Weights for 6-Row DX Coil and HGRH

Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Unit Piping - Condensate Drain Connection . . 11

Damper Assemblies. . . . . . . . . . . . . . . . . . . . . 12

Cabinet Weather Protection. . . . . . . . . . . . . . . 12

Installing Ductwork. . . . . . . . . . . . . . . . . . . . . . 12

Installing Duct Static Pressure Sensor Taps . . 12 Installing Building Static Pressure Sensor Taps 13

Electrical Installation . . . . . . . . . . . . . . . . . . . . . . 15

Field Power Wiring. . . . . . . . . . . . . . . . . . . . . . 15

Field Control Wiring . . . . . . . . . . . . . . . . . . . . . 16

Preparing Unit for Operation . . . . . . . . . . . . . . . . 17

Spring Isolated Fans . . . . . . . . . . . . . . . . . . . . 17

Optional Gas Heat . . . . . . . . . . . . . . . . . . . . . . . . . 18

Gas Furnace Design . . . . . . . . . . . . . . . . . . . . . . 18

Gas Heating Capacity Data . . . . . . . . . . . . . . . 18

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Gas Piping Routing Into Unit . . . . . . . . . . . . . . 22

Sequence of Operation (Staged Control) . . . . 23

Sequence of Operation (Modulating Burner). . 23

Start-Up Procedures . . . . . . . . . . . . . . . . . . . . 23

Operating Procedures . . . . . . . . . . . . . . . . . . . 25

Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Ignition Control Module for Gas Furnace. . . . . 26

Ignition Control Module for Modulating Gas Fur-

nace. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Variable Furnace Controller. . . . . . . . . . . . . . . 28

Optional Electric Heat . . . . . . . . . . . . . . . . . . . . . . 29

Electric Heater Design. . . . . . . . . . . . . . . . . . . . . 29

Electric Heating Capacity Data . . . . . . . . . . . . 29

Electric Heater Data. . . . . . . . . . . . . . . . . . . . . 29

Optional Modulating Hot Gas Reheat . . . . . . . . . 30

Modulating Hot Gas Reheat . . . . . . . . . . . . . . . . 30

Optional Hot Water Heat . . . . . . . . . . . . . . . . . . . . 33

Hot Water Heater Design . . . . . . . . . . . . . . . . . . 33

Hot Water Pressure Drop Data . . . . . . . . . . . . 34

Unit Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Economizer Enthalpy Control . . . . . . . . . . . . . 36

External Time Clock . . . . . . . . . . . . . . . . . . . . 36

Exhaust Fan Option . . . . . . . . . . . . . . . . . . . . 36

Proof-of-Airflow and Dirty Filter Switch . . . . . . 36

Duct High Pressure Limit . . . . . . . . . . . . . . . . 36

Convenience Receptacle (Field Powered) . . . 37

Convenience Receptacle (Unit Powered) . . . . 37

Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Sequence of Operation. . . . . . . . . . . . . . . . . . . . . 50

Operating States . . . . . . . . . . . . . . . . . . . . . . . . . 50

Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Recirculation . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Fan Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Minimum DAT . . . . . . . . . . . . . . . . . . . . . . . . . 50

Mechanical Cooling. . . . . . . . . . . . . . . . . . . . . 51

Economizer . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Check, Test, and Start Procedures . . . . . . . . . . . 52

Pre-Start of Unit . . . . . . . . . . . . . . . . . . . . . . . . . 52

Servicing Control Panel Components . . . . . . . 52

Before Start-Up . . . . . . . . . . . . . . . . . . . . . . . . 52

Power-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Fan Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Economizer Start-Up. . . . . . . . . . . . . . . . . . . . 52

Compressor Start-Up . . . . . . . . . . . . . . . . . . . 53

Sheave Alignment . . . . . . . . . . . . . . . . . . . . . . 54

Drive Belt Tension Adjustment . . . . . . . . . . . . 54

Air Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Final Control Settings. . . . . . . . . . . . . . . . . . . . . . 55

Controller Settings for Normal Operation . . . . . . 55

Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Performing Service Maintenance . . . . . . . . . . . . 56

Servicing Control Panel Components . . . . . . . 56

Planned Maintenance . . . . . . . . . . . . . . . . . . . 56

All-Aluminum Condenser Coils . . . . . . . . . . . . 56

Unit Storage . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Bearing Lubrication . . . . . . . . . . . . . . . . . . . . . 58

Setscrews . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Supply Fan Wheel-to-Funnel Alignment . . . . . 59

Refrigerant Charge . . . . . . . . . . . . . . . . . . . . . 59

Servicing Refrigerant Sensors or Switches. . . 59

Servicing Optional Electric Heater . . . . . . . . . 59

Service and Warranty Procedure . . . . . . . . . . . . 60

Replacement Parts . . . . . . . . . . . . . . . . . . . . . 60

Scroll Compressor. . . . . . . . . . . . . . . . . . . . . . 60

All Compressors . . . . . . . . . . . . . . . . . . . . . . . 60

In-Warranty Return Material Procedure . . . . . 60

Commercial Rooftop Equipment Warranty

Registration Form . . . . . . . . . . . . . . . . . . . . . . . . . 61

Quality Assurance Survey Report. . . . . . . . . . . . 63

Introduction

M P S – 015 – F G

McQuay Packaged System

Heat medium Y = None (cooling only) G = Natural gas E = Electric heat W = Hot water heat

Design vintage

Nominal capacity (tons)

General Information

Introduction

This manual provides general information about the “F” vintage McQuay Commercial Packaged Rooftop Unit model MPS. In addition to an overall description of the unit, it includes mechanical and electrical installation procedures, commissioning procedures, sequence of operation information, and maintenance instructions.

The MicroTech

III rooftop unit controller is available on “F” vintage rooftop units. For a detailed description of the MicroTech III components, input/output configurations, field wiring options and requirements, and service procedures, see OM 920. For operation and information on using and programming the MicroTech III unit controller, refer to the appropriate operation manual (see Table 1).

For a description of operation and information on using the keypad to view data and set parameters, refer to the

appropriate program-specific operation manual (see Table 1)

Table 1: Program Specific Unit Operation Literature

Rooftop unit control configuration Manual bulletin number

VFDs OM 844 - MD2

MPS Unit Controller

Discharge Air Control (VAV or CAV)

Space Comfort Control (SCC)

LonWorks Integration IM 918

BACnet Integration IM 917

BACnet IP Comm Module IM 916

OM 895 - MD3 OM 847 - MD6

OM 920

Unit Nameplate

The unit nameplate is located on the outside of the main control box door. It includes the unit model number, serial number, electrical characteristics, and refrigerant charge.

Hazard Identification Information

DANGER

Dangers indicate a hazardous situation which will result in death or serious injury if not avoided.

WARNING

Warnings indicate potentially hazardous situations, which can result in property damage, severe personal injury, or death if not avoided.

CAUTION

Cautions indicate potentially hazardous situations, which can result in personal injury or equipment damage if not avoided.

Nomenclature (MPS 015–050)

McQuay IM 1058 3

Mechanical Installation

Installer Responsibilities

The installation of this equipment shall be in accordance with the regulations of authorities having jurisdiction and all applicable codes. It is the responsibility of the installer to determine and follow the applicable codes.

CAUTION

Sharp edges on sheet metal and fasteners can cause personal injury. This equipment must be installed, operated,

and serviced only by an experienced installation company and fully trained personnel.

Receiving Inspection

When the equipment is received, all items should be carefully checked against the bill of lading to be sure all crates and cartons have been received. If the unit has become dirty

during shipment (winter road chemicals are of particular concern), clean it when received.

Figure 1: Service Clearances

All units should be carefully inspected for damage when received. Report all shipping damage to the carrier and file a claim. In most cases, equipment is shipped F.O.B. factory and claims for freight damage should be filed by the consignee.

Before unloading the unit, check the unit nameplate to make sure the voltage complies with the power supply available.

Service Clearance

Allow service clearances as approximately indicated in Figure 1. Also, McQuay recommends providing a roof walkway to the rooftop unit as well as along each side of the unit that provides access to most controls and serviceable components.

4 McQuay IM 1058

Mechanical Installation

Ventilation Clearance

Below are minimum ventilation clearance recommendations. The system designer must consider each application and provide adequate ventilation. If this is not done, the unit may not perform properly.

Unit(s) Surrounded by a Screen or a Fence:

1 The bottom of the screen or fence should be at least 1 ft.

(305 mm) above the roof surface.

2 The distance between the unit and a screen or fence should

be as described in Figure 1 on page 4.

3 The distance between any two units within a screen or

fence should be at least 120" (3048 mm).

Unit(s) Surrounded by Solid Walls:

1 If there are walls on one or two adjacent sides of the unit,

the walls may be any height. If there are walls on more than two adjacent sides of the unit, the walls should not be higher than the unit.

2 The distance between the unit and the wall should be at

least 96" (2438 mm) on all sides of the unit.

3 The distance between any two units within the walls should

be at least 120" (3048 mm).

Do not locate outside air intakes near sources of contaminated air.

If the unit is installed where windy conditions are common, install wind screens around the unit, maintaining the clearances specified (see Figure 1). This is particularly important to maintain adequate head pressure control when mechanical cooling is required at low outdoor air temperatures.

Note: Low head pressure may lead to poor and erratic

refrigerant feed control at the thermostatic expansion valve. The unit has automatic control of the condenser fans which should provide adequate head pressure control down to 20°F provided the unit is not exposed to windy conditions. The system designer is responsible for assuring the condensing section is not exposed to excessive wind or air recirculation.

Overhead Clearance

1 Unit(s) surrounded by screens or solid walls must have no

overhead obstructions over any part of the unit.

2 The area above the condenser must be unobstructed in all

installations to allow vertical air discharge.

3 The following restrictions must be observed for overhead

obstructions above the air handler section:

a There must be no overhead obstructions above the

furnace flue, or within 9" (229 mm) of the flue box.

b Overhead obstructions must be no less than 96"

(2438 mm) above the top of the unit.

c There must be no overhead obstructions in the areas

above the outside air and exhaust dampers that are farther than 24" (610 mm) from the side of the unit.

Roof Curb Assembly and Installation

Locate the roof curb and unit on a portion of the roof that can support the weight of the unit. The unit must be supported to prevent bending or twisting of the machine.

If building construction allows sound and vibration into the occupied space, locate the unit over a non-critical area. It is the responsibility of the system designer to make adequate provisions for noise and vibration in the occupied

space.

WARNING

Mold can cause personal injury. Some materials such as

gypsum wall board can promote mold growth when damp. Such materials must be protected from moisture that can enter units during maintenance or normal operation.

Install the curb and unit level to allow the condensate drain to flow properly and allow service access doors to open and close without binding.

The gasketed top surface of the curb seals against the unit when it is set on the curb. These flanges must not support the total weight of the duct work. See “Installing Ductwork” on page 12 for details on duct connections. It is critical that the condensate drain side of the unit be no higher than the opposite side.

Assembly Instructions

Assembly of a typical roof curb is shown in Figure 2.

1 Set curbing parts A thru G per dimensions shown over roof

opening or on a level surface. Note location of supply air opening. Check alignment of all mating screw holes.

2 Screw curbing parts together using fasteners provided.

Leave all screws loose until curb is checked to be square.

3 Square entire curbing assembly and securely tighten all

screws.

4 Position curb assembly over roof openings. Curb must be

level within .25 inches from side to side and 1.50 inches over its length. Check that top surface of curb is flat with no bowing or sagging.

5 Weld curb assembly in place. Caulk all seams watertight.

Remove backing from .25 x 1.50 wide gasket and apply to surfaces shown by crosshatching.

6 Check that electrical connections are coordinated.

McQuay IM 1058 5

Mechanical Installation

Figure 2: Roof Curb Assembly (MPS 030F – 035F Example)

6 McQuay IM 1058

Figure 3: Roof Curb Layout—MPS 015F – 025F

Mechanical Installation

McQuay IM 1058 7

23.50

[597 mm]

2.00

[51 mm]

2.00

[51 mm]

21.25

[540 mm]

71.38

[1813 mm]

15.87

[403 mm]

87.25

[2216 mm]

(INSIDE CURB)

1.25

[32 mm] TYP

1.63

[41 mm]

93.70

[2380 mm]

171.18 (INSIDE CURB) [4348 mm]

63.69

[1610 mm]

2.00

[51 mm]

2.00

[51 mm]

1.00

[26 mm]

1.00

[26 mm]

2.00

[51 mm]

2.38

[58 mm]

3.75

[95 mm]

PLAN VIEW

23.86

[606 mm]

CURB CROSS SECTION

KNOCKOUT DETAIL

HOT WATER

ONLY

CHASE

1.00

[25 mm]

19.00

[483 mm]

Mechanical Installation

Figure 4: Roof Curb Layout—MPS 030F – 035F

8 McQuay IM 1058

CURB CROSS SECTION

2.00

[51 mm]

2.00

[51 mm]

30.63

[778 mm]

87.25

[2216 mm]

(INSIDE CURB)

2.00

[51 mm]

1.25 TYP [32 mm]

1.63

[41 mm]

69.39

[1763 mm]

105.45

[2678 mm]

208.57 (INSIDE CURB) [5298 mm]

71.38

[1813 mm]

15.87

[403 mm]

28.25

[718 mm]

2.00

[51 mm]

2.00

[51 mm]

1.00

[25 mm]

2.28

[58 mm]

3.75

[95 mm]

28.92

[735 mm]

PLAN VIEW

1.00

[25 mm]

26.00

[660 mm]

HOT WATER

ONLY

CHASE

Figure 5: Roof Curb Layout—MPS 040F – 050F

Mechanical Installation

McQuay IM 1058 9

Mechanical Installation

LIFT UNIT ONLY AS SHOWN

SPREADER BARS REQUIRED

MUST USE ALL OF THESE

LIFTING LUGS FOR LIFTING UNIT.

Rigging and Handling

WARNING

Only trained and qualified personnel should be allowed to rig loads or operate load rated cranes and/or hoist assemblies. Do not use a forklift to lift or maneuver the unit. Failure to use a load rated crane or hoist assembly to lift or maneuver the unit can cause severe personal injury and property damage.

WARNING

Use all lifting points. Improper lifting can cause property damage, severe personal injury, or death.

CAUTION

Lifting points may not be symmetrical to the center of gravity of the unit. Ballast or unequal cable lengths may be

required.

Rigging holes for shackles are integral on the unit base. All six lifting points must be used for rigging the equipment. Use four independent lines, securing one end of a line to a unit base lifting point and the other end of the line to an associated spreader bar lifting point (see Figure 7). Figure 6

is an example of an instruction label shipped with each unit.

Figure 6: Rigging Label

Use spreader bars, 96" to 100" (2438 to 2540 mm) wide to prevent damage to the unit cabinet. Avoid twisting or uneven lifting of the unit. The cable length from the bracket to the hook should always be longer than the distance between the outer lifting points.

If the unit is stored at the construction site for an intermediate period, take these additional precautions:

1 Support the unit well along the length of the base rail.

2 Level the unit (no twists or uneven ground surface).

3 Provide proper drainage around the unit to prevent flooding

of the equipment.

4 Provide adequate protection from vandalism, mechanical

contact, etc.

5 Securely close the doors.

6 Cover the supply and return air openings.

Table 2 lists the weight distribution at each of the six lifting points on the unit (refer to Figure 7 on page 11). Table 3 details

lifting point locations.

Table 2: Percentage of Load and Weight Points

Unit (tons)

015 Cooling 2655 292 292 531 637 425 478

015 Gas Heating 2855 315 315 571 685 457 514

015 Electric Heating 2775 305 304 555 666 444 500

015 Hot Water Heating 2850 314 314 570 684 456 513

017 Cooling 2705 298 298 541 649 433 487

017 Gas Heating 2905 320 320 581 697 465 523

017 Electric Heating 2825 311 311 565 678 452 509

017 Hot Water Heating 2900 319 319 580 696 464 522

020 Cooling

020 Gas Heating

020 Electric Heating

020 Hot Water Heating

025 Cooling

025 Gas Heating

025 Electric Heating

025 Hot Water Heating

030 Cooling 3610 397 397 722 866 578 650

030 Gas Heating 3880 427 427 776 931 621 698

030 Electric Heating 3880 427 427 776 931 621 698

030 Hot Water Heating 3901 429 429 780 936 624 702

035 Cooling 3660 403 403 732 878 586 659

035 Gas Heating 3930 432 432 786 943 629 707

035 Electric Heating 3930 432 432 786 943 629 707

035 Hot Water Heating 3961 435 435 790 948 632 711

040 Cooling 4685 515 515 937 1124 750 843

040 Gas Heating 5035 554 554 1007 1208 806 906

040 Electric Heating 5035 554 554 1007 1208 806 906

040 Hot Water Heating 4992 549 549 998 1198 799 899

050 Cooling 4985 548 548 997 1196 798 897

050 Gas Heating 5335 587 587 1067 1280 854 960

050 Electric Heating 5335 587 587 1067 1280 854 960

050 Hot Water Heating 5292 582 582 1058 1270 847 953

Base unit weight includes Economizer, VFDs, and the smallest supply fan available (see Table 5 and Table 6 on page 11 for additional fan/motor weights).

Table 3: Weight Distribution Locations (see Figure 7)

Unit (Tons)

015–035 Ton Unit 35.5 62.0 52.0 040–050 Ton Unit 40.0 69.0 89.0

Table 4: Curb Weights

Unit (Tons) / Curb

Height

015–035 / 14" Curb 341 015–035 / 24" Curb 501 040–050 / 14" Curb 481 040–050 / 24" Curb 708

Table 4 lists the weights of unit curbs.

Tot al

Weight

(lbs)*

2955 325 325 591 709 473 532 3155 347 347 631 757 505 568 3075 338 338 615 738 492 554 3150 347 347 630 756 504 567 3055 336 336 611 733 489 550 3255 358 358 651 781 521 586 3175 349 349 635 762 508 572 3250 358 358 650 780 520 585

11%B11%C20%D24%E16%F18%

L1 L2 L3

Weight (lbs)

Point

% of Total Load

Distance

10 McQuay IM 1058

Mechanical Installation

Figure 7: Rigging the Unit (MPS 030 – 035 Example)

Additional Weights for Motors/Exhaust Fans

Table 5: Additional Weights - Motors/Exhaust Fans (20 - 25 ton units)

1 0 15 - 25 150

1.5 9 29 332 543

Table 6: Additional Weights - Motors/Exhaust Fans (30 - 50 ton units)

7.5 0 30 150

10 25 35 150 15 125 40 200 20 175 50 200 25 225 30 275

Additional Motor

Weight (lbs)

Additional Motor

Weight (lbs)

Unit

(tons)

Unit

(tons)

Additional Exhaust

Fan Weight (lbs)

Additional Exhaust

Fan Weight (lbs)

Unit Piping - Condensate Drain Connection

The unit is provided with a 1" female NPT condensate drain connection. For proper drainage, level the unit and drain pan side to side and install a P-trap.

Figure 8 shows the layout of the condensate drain connection. The distance from the drain pan outlet to the horizontal run of the P-trap should be a distance of twice the static pressure in the drain pan.

Example: If the static pressure as measured in the drain pan is

1.5", then the distance between the drain outlet and the horizontal run should be 3".

Draining condensate directly onto the roof may be acceptable; refer to local codes. Provide a small drip pad of stone, mortar, wood, or metal to protect the roof against possible damage.

If condensate is piped into the building drainage system, pitch the drain line away from the unit a minimum of 1/8" per foot. The drain line must penetrate the roof external to the unit. Refer to local codes for additional requirements. Sealed drain lines require venting to provide proper condensate flow.

Where the cooling coils have intermediate condensate pans on the face of the evaporator coil, copper tubes near both ends of the coil supply drainage to the main drain pan. Verify the tubes are in place and open before putting the unit into operation.

Periodically clean to prevent microbial growth/algae buildup from plugging the drain and causing the drain pan to overflow. Clean drain pans to prevent the spread of disease. Cleaning

should be performed by qualified personnel

WARNING

Drain pans must be cleaned periodically. Material in uncleaned drain pans can cause disease.

Cleaning should be performed by qualified personnel.

Figure 8: Condensate Drain Connection

Static Pressure (P) at the Drain Pan

Additional Weights for 6-Row DX Coil and HGRH Coil

Table 7: Coil Weights

Unit

15–25 118 70 30–35 164 82

40 187 92 50 231 92

McQuay IM 1058 11

Weight (lbs)

6 Row DX HGRH

Mechanical Installation

Damper Assemblies

The optional damper assemblies described in this section are ordered with factory-installed actuators and linkages. The following sections describe the operation and linkage adjustment of the factory option.

Figure 9: Damper Assembly

Economizer Dampers

As the single actuator modulates, the outside air dampers open, the return air dampers close, and the exhaust air exits the unit through the gravity relief dampers.

The economizer comes with manually adjustable linkage (Figure 9). The damper is set so that the crankarm moves through a 90-degree angle to bring the economizer dampers from full open to full close. Mechanical stops are placed in the crankarm mounting bracket. Do not remove stops. Driving the crankarm past the stops results in damage to the linkage or damper.

Outdoor Air Dampers (0% to 30%)

These dampers are intended to remain at a fixed position during unit operation, providing fresh air quantities from 0 to 30% of the total system airflow, depending on the damper setting.

The damper position may be set at the unit controller keypad (refer to OM 920 for further detail). During unit operation, the damper is driven to the position set at the unit controller. During the off cycle, the damper is automatically closed.

Cabinet Weather Protection

This unit ships from the factory with fully gasketed access doors and cabinet caulking to provide weather resistant operation. After the unit is set in place, inspect all door gaskets for shipping damage and replace if necessary.

Protect the unit from overhead runoff from overhangs or other such structures.

CAUTION

Transportation, rigging, or maintenance can damage the unit’s weather seal. Periodically inspect the unit for leakage.

Standing moisture can promote microbial growth, disease, or damage to the equipment and building.

Installing Ductwork

On vertical-supply/vertical-return units, if a McQuay roof curb is not used, the installing contractor should make an airtight connection by attaching field fabricated duct collars to the bottom surface of the unit’s duct opening. Do not support the total weight of the duct work from the unit. See Figure 4 on page 8 or Figure 5 on page 9.

Use flexible connections between the unit and ductwork to avoid transmission of vibration from the unit to the structure.

To minimize losses and sound transmission, design duct work per ASHRAE and SMACNA recommendations.

Where return air ducts are not required, connect a sound absorbing T or L section to the unit return to reduce noise

transmission to the occupied space.

WARNING

Mold can cause personal injury. Materials such as gypsum

wall board can promote mold growth when damp. Such materials must be protected from moisture that can enter units during maintenance or normal operation.

Ductwork exposed to outdoor conditions must be built in accordance with ASHRAE and SMACNA recommendations

and local building codes

Installing Duct Static Pressure Sensor Taps

For all VAV units, duct static pressure taps must be field installed and connected to the static pressure sensor 1 (SPS1) in the unit. Sensor SPS1 is standard on VAV units and is located in the main control panel.

Carefully locate and install the duct static pressure sensing tap. Improperly locating or installing the sensing tap causes unsatisfactory operation of the entire variable air volume system. Below are pressure tap location and installation recommendations. The installation must comply with local code requirements.

12 McQuay IM 1058

Mechanical Installation

Roof

SPS1

Main Control Panel

Condenser Section

HI Line

LO Line

Remote Sense Point

To Sensor HI Input

Pressure Sensing Tubing

Tubing Extends Through Approx. 1/8”

Rubber Grommet

Ductwork (Remote Location)

To Sensor LO Input

1 Install a tee fitting with a leak-tight removable cap in each

tube near the sensor fitting. This facilitates connecting a manometer or pressure gauge if testing is required.

2 Use different colored tubing for the duct pressure (HI) and

reference pressure (LO) taps, or tag the tubes. McQuay recommends 1/8" ID tubing.

3 Locate the duct pressure (HI) tap near the end of a long

duct to ensure that all terminal box take-offs along the run have adequate static pressure.

4 Locate the duct tap in a nonturbulent flow area of the duct.

Keep it several duct diameters away from take-off points, bends, neckdowns, attenuators, vanes, or other irregularities.

5 Use a static pressure tip (Dwyer A302 or equivalent) or the

bare end of the plastic tubing for the duct tap. (If the duct is lined inside, use a static pressure tip device.)

6 Install the duct tap so that it senses only static pressure (not

velocity pressure). If a bare tube end is used, it must be smooth, square (not cut at an angle) and perpendicular to the airstream (see Figure 11).

7 Locate the reference pressure (LO) tap near the duct

pressure tap within the building. If the tap is not connected to the sensor, unsatisfactory operation will result.

8 Route the tubes through the curb and feed them into the

unit through the knockout in the bottom of the control panel (see Figure 10). Connect the tubes to appropriate barbed fittings (on SPS1) in the control panel. (Fittings are sized to accept 1/8" ID tubing.)

Figure 10: Static Pressure Tubing Knockout Location

Figure 11: Duct Static Pressure Sensing Tubing Installation

Installing Building Static Pressure Sensor Taps

If a unit has building static pressure control capability, you must field install and connect static pressure taps to the static pressure sensor SPS2 in the unit. This sensor is located at the bottom of the main control panel next to SPS1.

Carefully locate and install the two static pressure sensing taps. Improper location or installation of the sensor taps causes unsatisfactory operation. Below are pressure tap location and installation recommendations for both building envelope and lab, or “space within a space” pressure control applications.

The installation must comply with local code requirements.

CAUTION

Fragile sensor fittings. If you must remove tubing from a

pressure sensor fitting, use care. Do not use excessive force or wrench the tubing back and forth to remove or the fitting can break off and damage sensor.

McQuay IM 1058 13

Mechanical Installation

Building Pressurization Applications

1 Install a tee fitting with a leak-tight removable cap in each

tube near the sensor fitting. This facilitates connecting a manometer or pressure gauge if testing is required.

2 Locate the building pressure (high) tap in the area that

requires the closest control. Typically, this is a ground level floor that has doors to the outside.

3 Locate the building tap so it is not influenced by any source

of moving air (velocity pressure). These sources may include air diffusers or outside doors.

4 Route the building tap tube through the curb and feed it into

the unit through the knockout in the bottom of the control panel (refer to Figure 10). Connect the 1/8" ID tube to the (high) fitting for sensor SPS2.

5 Locate the reference pressure (low) tap on the roof. Keep it

away from the condenser fans, walls, or anything else that may cause air turbulence. Mount it high enough above the roof so it is not affected by snow. Not connecting the reference tap to the sensor results in unsatisfactory operation.

6 Use an outdoor static pressure tip (Dwyer A306 or

equivalent) to minimize the adverse effects of wind. Place some type of screen over the sensor to keep out insects. Loosely packed cotton works well.

7 Route the outdoor tap tube out of the main control panel

through a small field-cut opening in the upright. Seal the penetration to prevent water from entering. Connect the 1/8" ID tube to the (low) fitting for sensor SPS2.

Lab Pressurization Applications

1 Install a “T” fitting with a leak-tight removable cap in each

tube near the sensor fitting. This facilitates connecting a manometer or pressure gauge if testing is required.

2 Use different colored tubing for the controlled space

pressure (high) and reference pressure (low) taps, or tag the tubes.

3 Regardless whether the controlled space is positive or

negative with respect to its reference, locate the high pressure tap in the controlled space (the setpoint can be set between -0.2" and 0.2" wc).

4 Locate the reference pressure (low) tap in the area

surrounding the controlled space. Not locating the reference tap to the sensor results in unsatisfactory operation.

5 Locate both taps so they are not influenced by any source

of moving air (velocity pressure). These sources may include air diffusers or doors between the high and low pressure areas.

6 Route the building tap tube between the curb and the

supply duct and feed it into the unit through the knockout in the bottom of the control panel.

7 Connect the tube to the (high) fitting for sensor SPS2.

Figure 12: Outdoor Static Pressure Tubing Installation

14 McQuay IM 1058

Electrical Installation

Field Power Wiring

Wiring must comply with all applicable codes and ordinances. The warranty is voided if wiring is not in accordance with these specifications.

According to the National Electrical Code, a disconnecting means shall be located within sight of and readily accessible from the air conditioning equipment. The unit can be ordered with an optional factory mounted disconnect switch. This switch is not fused. Power leads must be over-current protected at the point of distribution. The maximum rated overcurrent protection device (MROPD) value appears on the unit nameplate.

All Units

All units are provided with internal power wiring for single point power connection. The power block or an optional disconnect switch is located within the main control panel. Field power leads are brought into the unit through knockouts in the bottom of the main control panel (see Figure 13 and also Table 8). Refer to the unit nameplate to determine the number of power connections.

WARNING

Hazardous voltage. Can cause severe injury or death.

Disconnect electric power before servicing equipment. More than one disconnect may be required to de-energize the unit.

Note: To wire entry points, refer to certified drawings for

dimensions.

Figure 13: MPS Power Wiring Knockout Locations

The preferred entrance for power cables is through the bottom knockouts provided on the unit. If a side entrance is the only option, a hole may be drilled in the stationary upright.

The minimum circuit ampacity (MCA) is shown on the unit nameplate. Refer to Table 8 for the recommended number of power wires.

Copper wire is required for all conductors. Size wires in accordance with the ampacity tables in Article 310 of the National Electrical Code. If long wires are required, it may be necessary to increase the wire size to prevent excessive voltage drop. Wires should be sized for a maximum of 3% voltage drop. Supply voltage must not vary by more than 10% of nameplate. Phase voltage imbalance must not exceed 2%. (Calculate the average voltage of the three legs. The leg with voltage deviating the farthest from the average value must not be more than 2% away.) Contact the local power company for correction of improper voltage or phase imbalance.

CAUTION

Provide proper line voltage and phase balance.

Improper line voltage or excessive phase imbalance constitutes product abuse. It can cause severe damage to the unit's electrical components.

A ground lug is provided in the control panel. Size the grounding conductor in accordance with Table 250-95 of the National Electrical Code.

In compliance with the National Electrical Code, a 115 V factory mounted service receptacle outlet is provided. This outlet must be powered by a field connected 15 A, 115 V power supply. Leads are brought into the unit through a 7/8" knockout in the bottom of the main control panel.

Table 8: Recommended Field Power Wiring

Ampacity

(MCA)

30 1 10 75 40 1 8 75 55 1 6 75 70 1 4 75 85 1 3 75

95 1 2 75 130 1 1 75 150 1 1/0 75 175 1 2/0 75 200 1 3/0 75 230 1 4/0 75 255 1 250 75 300 2 1/0 75 350 2 2/0 75 400 2 3/0 75 460 2 4/0 75 510 2 250 75 600 3 3/0 75 690 3 4/0 75 765 3 250 75

Notes:

1. All wire sizes assume separate conduit for each set of parallel conductors.

2. All wire sizes based on NEC Table 310-16 for 75°C THW wire (copper). Canadian electrical code wire ampacities may vary.

3. All wire sizes assume no voltage drop for short power leads.

# of Power

Wires Per

Phase

Wire Gauge

Insulation

Temperature

Rating (°C)

McQuay IM 1058 15

Electrical Installation

Field Control Wiring

The Maverick rooftop units are available with the following field control connections:

• Space sensor.

• Space sensor with setpoint adjustment.

• Fan operation output.

• VAV box output.

• Remote alarm output.

• External discharge air temperature reset.

• Outdoor air damper minimum position adjustment.

Descriptions of these field connections are included in the MicroTech III Unit Controller manual (OM 920).

WARNING

Electrical shock hazard. Can cause severe injury or death.

Connect only low voltage NEC Class II circuits to terminal block TB2.

16 McQuay IM 1058

Preparing Unit for Operation

Spring Isolated Fans

WARNING

Moving machinery hazard. Can cause severe injury or death. Before servicing equipment, disconnect power and lock

off. More than one disconnect may be required to de-energize unit. Prior to operating the fans for the first time, refer to “Check, Test, and Start Procedures” on page 52.

Releasing Spring Mounts

The spring-mounted supply fan is locked down with four shipping bolts for shipment. Remove each shipping bolt before operating the fans. Figure 14 shows a typical spring mount with a height adjustment nut and a shipping bolt.

After removing the shipping bolts, rock the fan assembly by hand to check for freedom of movement.

Figure 14: Spring Mounts

Adjusting Spring Mounts

During operation all fans should ride level. Level the fan assembly by performing the following:

1 Loosen the 3/8" cap screw (do not remove).

2 Loosen the spring cap nut.

3 Rotate the 5/8" adjustment nut counter-clockwise to raise

the fan assembly, or clockwise to lower the fan assembly.

4 Tighten the 3/8" cap screw.

5 Tighten the spring cap nut.

McQuay IM 1058 17

Optional Gas Heat

Gas Furnace Design

If the 8th digit in the model number is a “G”, the rooftop unit was furnished with a factory installed furnace (Example, MPS035FG). The Maverick commercial rooftop units are available with either the low heat input or the high heat input furnace (see capacities in Table 9). This packaged gas heat rooftop unit is designed for outdoor non-residential installations only.

The gas heat furnace design consists of a tubular heat exchanger, in-shot burner manifold with gas valve, induced combustion blower, gas heat DDC control module and all operational safeties. The tubular heat exchanger can come with the standard aluminized steel construction or the optional stainless steel construction. The safety switches include a highlimit temperature switch (Figure 15), an auxiliary high-limit switch (Figure 15), a combustion blower proof of airflow (see Figure 16), and the flame roll-out switch (see Figure 16).

The high limit switch is an automatic reset switch and it opens up at 160°F to shut the furnace down and closes at 130°F. The auxiliary limit switch is a manual reset and opens up at 180°F to shut the furnace down.

Figure 15: Gas Heat Section

Gas Heating Capacity Data

Table 9: MPS 020E – 050E Gas Heating Capacities

Unit Size

Data

Heating Input (MBh) 240 480 300 600 400 800

Heating Output (MBh) 192 384 240 480 320 640

Steady State Efficiency 80% 80% 80% 80% 80% 80%

Number of Stages 2 4 2 4 2 4

Turndown

Minimum Airflow 2960 5920 3700 7400 4900 9800

Maximum Temperature

Gas Main Pressure

Natural Gas (in. wc) 7-14 7-14 7-14 7-14 7-14 7-14

Liquid Propane (in. wc) 12-14 12-14 12-14 12-14 12-14 12-14

Manifold Pressure Natural Gas (per gas valve)

Stage 1 (in. wc) 1.2 1.2 1.2 1.2 1.2 1.2 Stage 2 (in. wc) 3.2 3.2 3.2 3.2 3.2 3.2

Low fire

Propane

Stage 1 (in. wc) 2.3 2.3 2.3 2.3 2.3 2.3 Stage 2 (in. wc) 10.0 10.0 10.0 10.0 10.0 10.0

Low fire

Note: 1 Modulating gas heat only.

Modulating gas heat not available with propane.

Rise

015 -025 030 - 035 040 - 050

Low Heat High Heat Low Heat High Heat Low Heat High Heat

4:18:14:18:14:18:1

60°F 60°F 60°F 60°F 60°F 60°F

0.40.40.40.40.40.4

N/A N/A N/A N/A N/A N/A

18 McQuay IM 1058

Figure 16: Staged Furnace Assembly

Optional Gas Heat

Warranty Exclusion

Warranty is void if the furnace is operated in the presence of chlorinated vapors, if the airflow through the furnace is not in accordance with rating plate, or if the wiring or controls have

been modified or tampered with.

WARNING

Hot surface hazard. Can cause severe equipment damage, personal injury, or death. Allow burner assembly to cool

before servicing equipment.

WARNING

Units equipped with gas heating must not be operated in an atmosphere contaminated with chemicals which will corrode the unit such as halogenated hydrocarbons, chlorine, cleaning solvents, refrigerants, swimming pool exhaust, etc. Exposure to these compounds may cause severe damage to the gas furnace and result in improper or dangerous operation. Operation of the gas furnace in such

a contaminated atmosphere constitutes product abuse and will void all warranty coverage by the manufacturer. Questions regarding specific contaminants should be referred to your local gas utility.

Ventilation & Flue Pipe Requirements

The McQuay rooftop unit is equipped with an outdoor air hood to supply adequate combustion air. The unit also has a flue outlet assembly and requires no additional chimney, flue pipe, Breidert cap, draft inducer, etc.

Factory Checkout

This complete furnace was fired and tested at the factory. The unit was fired through several complete sequences of start-up through shutoff to check operation. A check was made of the air switch, gas pressure switch, high limit operation.

This checkout normally eliminates on-the-job start-up problems; however, the equipment is subject to variable job conditions and shipping shocks can change adjustments, cause damage, and loosen connections and fasteners. Therefore, it is necessary to go through the complete start-up procedure even though the unit may appear to be operating properly.

McQuay IM 1058 19

Optional Gas Heat

Installation

IMPORTANT

This furnace must be installed by an experienced professional installation company that employs fully trained and experienced technicians. Install the furnace in accordance with the manufacturer's instructions and local codes. In the absence of local codes, follow the National Fuel Gas Code, ANSI Z223.1/NFPA 54, or the CSA B149.1, Natural Gas and Propane Installation Code.

WARNING

Sharp edges hazard. Can cause personal injury or death.

Sheet metal parts, self-tapping screws, clips, and similar items inherently have sharp edges, and it is necessary that the installer exercise caution when handling these items.

Flue Box

The flue box (Figure 17) is not installed at the factory because it would increase the width of the unit beyond the allowable shipping width.

Figure 17: Flue Box Installation

3 Line assembly holes up.

4 Install screws to fasten the flue box to the side of the unit.

Outdoor Air (OA) Hood

The OA hood (Figure 18) is not installed at the factory because it would increase the width of the unit beyond the allowable shipping width. The hood is shipped in a box in the fan section.

Figure 18: Outdoor Air (OA) Hood Installation

The OA hoods must be installed over the outdoor air openings as shown in Figure 18.

1 Remove and discard the shipping covers.

2 Position the hood over the OA openings.

3 Line assembly holes up.

4 Install screws to fasten the OA hood.

The OA hoods must be installed before the furnace is operated. The flue box must be installed over the combustion exhaust openings shown in Figure 17. All holes are prepunched, the fasteners are furnished and everything is shipped inside the fan section.

1 Remove and discard the shipping covers.

2 Position the flue box over the exhaust openings.

20 McQuay IM 1058

Optional Gas Heat

Electrical

The McQuay burner receives its electrical power from the main unit control panel. No additional power wiring must be routed to the burner. The sequencing of the burner is also controlled through this panel and therefore is factory wired. No additional wiring will be required.

DANGER

If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injury, or loss of life. A. This appliance does not have a pilot. It is equipped with an

ignition device which automatically lights the burner. Do not try to light the burner by hand. B. Before operating, smell all around the appliance area for gas. Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor.

WHAT TO DO IF YOU SMELL GAS:

• Do not try to light any appliance.

• Do not touch any electric switch, do not use any phone in

your building.

• Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.

• If you cannot reach your gas supplier, call the fire department.

C. Use only your hand to push in or turn the gas control knob. Never use tools. If the knob will not push in or turn by hand, don't try to repair it, call a qualified service technician. Force or attempted repair may result in a fire or explosion. D. Do not use this appliance if any part has been under water. Immediately call a qualified service technician to inspect the appliance and to replace any part of the control system and any gas control which has been under water.

Gas Piping

Gas piping must be sized to provide the minimum required pressure at the burner when the burner is operating at maximum input. Consult your local utility on any questions on gas pressure available, allowing piping pressure drops, and local piping requirements.

Install all piping in accordance with the National Fuel Gas Code (ANSI Z223.1), (NFPA 54-1999) and any applicable local codes.

The proper size piping must be run from the meter to the gas burner without reductions. Undersized piping will result in inadequate pressure at the burner. The pressure will be at its lowest when it is needed the most, at times of maximum demand. Therefore, it can cause intermittent hard-to-find problems because the problem may have left before the service technician has arrived. Avoid the use of bushings wherever possible.

Remove all burrs and obstructions from pipe. Do not bend pipe; use elbows or other pipe fittings to properly locate pipe.

A drip leg and a manual shut-off must be installed in the vertical line before each burner such that it will not freeze. Install unions so gas train components can be removed for service. All pipe threads must have a pipe dope which is resistant to the action of LP gas. After installation, pressurize the piping as required and test all joints for tightness with a rich soap solution. Any bubbling is considered a leak and must be eliminated. Do not use a match or flame to locate leaks.

Gas Pressure Requirements

The pressure furnished to the main gas valve must not exceed

13.9" wc. When the supply pressure is above 13.9" wc, a high pressure regulator must precede the appliance gas pressure regulator. The inlet gas pressure must not exceed the maximum pressure rating of the high pressure regulator, and the outlet pressure must furnish gas to the appliance pressure regulator within the pressure range mentioned above.

McQuay IM 1058 21

Optional Gas Heat

Table 10: Capacity of Pipe Natural Gas (CFH)

With Pressure Drop of 0.3" Wc & Specific Gravity Of 0.60

Pipe

Length (ft.)

10 132 278 520 1050 1600 2050 4800 8500 17500

20 92 190 350 730 1100 2100 3300 5900 12000

30 73 152 285 590 890 1650 2700 4700 9700

40 63 130 245 500 760 1450 2300 4100 8300

50 56 115 215 440 670 1270 2000 3600 7400

60 50 105 195 400 610 1150 1850 3250 6800

70 46 96 180 370 560 1050 1700 3000 6200

80 53 90 170 350 530 990 1600 2800 5800

90 40 84 160 320 490 930 1500 2600 5400

100 38 79 150 305 460 870 1400 2500 5100

125 34 72 130 275 410 780 1250 2200 4500

150 31 64 120 250 380 710 1130 2000 4100

175 28 59 110 225 350 650 1050 1850 3800

200 26 55 100 210 320 610 980 1700 3500

NOTE: Use multiplier below for other gravities and pressure drops.

½ ¾ 1 1¼ 1½ 2 2½ 3 4

Pipe Size-inches (Ips)

Table 11: Specific Gravity Other Than 0.60

Specific Gravity Multiplier

0.50 1.100

0.60 1.000

0.70 0.936

0.80 0.867

0.90 0.816

1.00 0.775

PROPANE-AIR

1.10 0.740

PROPANE

1.55 0.622

BUTANE

2.00 0.547

Table 12: Pressure Drop Other Than 0.3"

Pressure Drop Multiplier Pressure Multiplier

0.1 0.577 1.0 1.83

0.2 0.815 2.0 2.58

0.3 1.000 3.0 3.16

0.4 1.16 4.0 3.65

0.6 1.42 6.0 4.47

0.8 1.64 8.0 5.15

Gas Piping Routing Into Unit

On-The-Roof Piping

1 Remove knockout on upright (refer to Figure 19).

2 Route gas supply pipe through hole. Carefully plan pipe

route and fitting locations to avoid interference with swinging of doors, etc.

Figure 19: Piping Schematic

22 McQuay IM 1058

Optional Gas Heat

Sequence of Operation (Staged Control)

Low Heat Option (2 Stage Control)

The following details the sequence of operation for the low heat option.

1 Unit DDC control calls for heat.

2 Furnace DDC control module receives a call for heat.

3 High limit switch is checked for safe condition.

4 Proof of airflow switch is check for combustion airflow.

5 60 second prepurge cycle starts.

6 Spark ignitor is activated for 3 seconds.

7 Gas valve receives a command for stage 1 of heat.

8 Burner is ignited.

9 Unit DDC controller calls for stage 2 of heat.

10 Furnace DDC controller receives a stage 2 heat command.

11 Gas valve receives a command for stage 2 of heat.

High Heat Option (4 Stage Control)

For a unit with the optional high heat the above sequence is followed for the first two stages.

For the remaining 2 stages the above procedure is repeated on the second furnace module.

Sequence of Operation (Modulating Burner)

Low Heat Option with Modulation

The following details the sequence of operation for the low heat option.

1 Unit DDC controller calls for heat.

2 Furnace DDC control module receives a call for heat.

3 Furnace safety switches and DDC control are checked for

safe conditions.

4 45 second prepurge cycle starts. Proof of airflow switch is

checked for combustion airflows.

5 Spark ignitor is activated.

6 Gas valve receives a signal to open fully.

7 Burner is ignited and runs for 20 seconds in high fire. Note:

if call for heat is interrupted during this timing, the furnace will be locked in for the 20 seconds cycle.

8 Gas valve and induction blower motor receives a signal to

modulate burner output to match the unit discharge air temperature setting.

2 Top Furnace DDC control module receives a call for heat.

3 High limit switch is checked for safe condition.

4 Proof of airflow switch is checked for combustion airflow.

5 45 second prepurge cycle starts.

6 Spark ignitor is activated.

7 Gas valve receives a signal to open fully.

8 Burner is ignited and runs for 30 seconds in high fire

9 Modulating burner gas valve and induction blower motor

receives a signal to modulate burner output to match the unit discharge air temperature setting.

10 If modulating burner is unable to meet discharge

temperature set point, furnace DDC control calls for third stage of heating. The top furnace is reduced to low (50%) fire. The bottom furnace is sequenced on per stage furnaces sequence of operation (steps 2 - 8).

11 Staged burner gas valve receives a signal to open to 50%.

12 Modulating burner gas valve and induction blower motor

receives a signal to modulate burner output to match the unit discharge air temperature setting.

13 If stage 3 and modulating furnace is unable to meet

discharge temperature setpoint, furnace DDC controller calls for stage 4 heat. The bottom furnace will stage up to high fire and the modulating furnace will reduce to 50% operation.

14 Staged burner gas valve receives a signal to open fully.

15 Modulating furnace's gas valve and induction blower motor

receives a signal to modulate burner output to match the unit discharge air temperature setting.

Start-Up Procedures

Start-Up Responsibility

The start-up organization is responsible for determining that the furnace, as installed and as applied, will operate within the limits specified on the furnace rating plate.

1 The furnace must not operate at an airflow below the

specified Minimum Airflow CFM (refer to Table 9 on page 18). On variable air volume systems it must be determined that the furnace will not be operated if or when system cfm is reduced below the specified minimum airflow cfm.

2 It must be established that the gas supply is within the

proper pressure range (refer to Table 9 on page 18).

High Heat Option with Modulation

The following details the sequence of operation for the high heat option. This option includes dual burners with one being modulating and the other being 2 stage control.

1 Unit DDC controller calls for heat.

McQuay IM 1058 23

Optional Gas Heat

Start-up and service of this equipment must be performed by trained and experienced technicians. It is highly

recommended that the initial start-up and future service be performed by McQuay trained technicians who are familiar with working on live equipment. A representative of the owner or the operator of the equipment should be present during startup to receive instructions in the operation, care and adjustment of the unit.

WARNING

Overheating or failure of the gas supply to shut off can cause equipment damage, severe personal injury or death. Turn off the manual gas valve to the appliance before

shutting off the electrical supply.

Before Start-Up

1 Notify inspectors or representatives who may be required

to be present during start-up of gas fuel equipment. These could include the gas utility company, city gas inspectors, heating inspectors, etc.

2 Review the equipment and service literature and become

familiar with the location and purpose of the furnace controls. Determine where the gas and power can be turned off at the unit and before the unit.

3 Determine that power is connected to the unit and

available.

4 Determine that the gas piping, meter, and service regulator

have been installed, tested, and meet the equipment requirements.

5 Determine that proper instruments will be available for the

start-up. A proper start-up requires the following: voltmeter, manometer or gauges with ranges for both manifold pressure and inlet gas pressure.

Start-Up Preliminary

Close gas main.

1 Check the burner fan wheel for binding, rubbing, or loose

setscrews.

2 Check power.

3 Purge the gas lines.

4 Leak check. Using a rich soap-water mixture and a brush,

check the gas lines for leaks. Correct all leaks before starting furnace.

24 McQuay IM 1058

Optional Gas Heat

Operating Procedures

DANGER

WHAT TO DO IF YOU SMELL GAS:

• Do not try to light any appliance.

• Do not touch any electric switch, do not use any phone in

your building.

• Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.

• If you cannot reach your gas supplier, call the fire department.

1 Set the thermostat to the lowest setting.

2 Turn off all electric power to the appliance.

3 This appliance is equipped with an ignition device which

automatically lights the burner. Do NOT try to light the pilot by hand.

4 Open the control access panel.

5 Turn the gas control clockwise to “OFF”.

6 Wait five (5) minutes to clear out any gas. Then, smell for

gas, including near the floor. If you smell gas, STOP! Follow step “B” in the DANGER label on this page. If you don't smell gas, proceed to the next step.

7 Turn the gas control counter-clockwise to “ON”.

8 Close the control access panel.

9 Turn on all electric power to the appliance.

10 Set thermostat to desired setting.

11 If the appliance will not operate, refer to “Turning Off Gas

to the Appliance”, and call your service technician or gas supplier.

Turning Off Gas to the Appliance

1 Set the thermostat to the lowest setting.

2 Turn off all electrical power to the appliance if service is to

be performed.

3 Open the control access panel.

4 Turn the gas control knob clockwise to “OFF”. Do not

force.

5 Close the control access panel.

Service

The furnace DDC controller has diagnostic information for troubleshooting the furnace operation. The ignition control module has a LED light that will flash when an abnormal condition occurs. See Figure 20 for an explanation of the diagnostic information.

Maintenance

Planned maintenance is the best way to avoid unnecessary expense and inconvenience. Have this system inspected at regular intervals by a trained and experienced service technician. The following service intervals are typical for average situations but will have to be adjusted to suit your particular circumstances.

Fuel pressure settings and control settings should be made only by persons thoroughly experienced with the burner and control system, and must not be tampered with by persons without such experience.

Always replace covers on burner controls and boxes as the electrical contacts are sensitive to dust and dirt. Perform maintenance of controls, gas valves, and other components in accordance with instructions contained in the manufacturer's bulletins.

Monthly

Check air filters and replace if dirty.

Twice Yearly

1 Burner Air - Check burner fan wheel for dirt buildup and

lint. Check combustion air intake louver and flue box for dirt buildup and accumulation of windborne debris.

2 Cleaning - Inspect flue tubes and combustion chamber,

cleaning as required. Keep burner vestibule clean. Dirt and debris can result in burner air blockages.

Yearly

Gas Train - Check all valves, piping and connections for leakage. Inspect and clean flame rod, ignition electrode, and burner manifold.

Condensate Pan/Drain/P-Trap - Check pan, drain, and ptraps for accumulation of debris. Check that p-traps are filled with water at the start of each cooling season.

McQuay IM 1058 25

Optional Gas Heat

L1 IND

COM

2 Stage Gas

Valve

HIMV

L1 L2

40VA

Gnd

1016-427 Ignition Module

1/4" quick connect termination to harness

Igniter

PS1

PS2

ROS1

APS

ROS2

Flame Sensor

Terminal Block

Comb Fan

Motor

24VAC

115VAC

APS Airflow Proving Switch ROS1 Roll Out Switch #1 ROS2 Roll Out Switch #2

from main control panel

Ignition Control Module for Gas Furnace

Figure 20: Typical Staged Gas Furnace Electrical Schematic with Sensor

Ignition Control Module LED Diagnostics

The following LED indicators can be used to diagnose faults associated with the staged gas furnace.

Table 13: LED Indicator and Fault Conditions

Indicator Fault Condition

Steady Off No power or control hardware fault Steady On Power applied, control OK

1 Flash Combustion fan motor energized, pressure

2 Flashes Combustion fan motor off, pressure switch

3 Flashes Ignition lockout from too many trials 4 Flashes Ignition lockout from too many flame losses

5 Flashes Control hardware fault detected

switch open

closed

within single call for heat

26 McQuay IM 1058

Optional Gas Heat

1/4" Quick Connec t Termination

Terminal Block

APS Airow Prov ing Sw itch ROS1 Roll Out Switch #1 ROS2 Roll Out Switch #2

40VA

24VAC

115 VAC

Neutral

Ground

120 VAC

T1 T3

Neutral

Hot

Neutral

Variable

Inducer

Inducer HS I

Flame

Flame Sensor

24V AC

115 VAC

Spark Electrode

ROS1

APS

ROS2

Sensing hose to fan

Press u re

Tr ans du cer

Modulating

Gas Valve

24VAC

GND

MOD

RTN

MOD

RTN

Combustion Board

Limit

Press

Switch

DSI

Board

L1 L2

0-10V DC

input signal

Comm Port

Status

LED

WHT

BLK

WHT

BLU

RED

WHT

GRY

ORG

WHT

BLK

WHT

BLK

WHT

BLK

GRN

WHT

BLK

Gn d

GRY

RED

BLU

BRN

RED

Ignition Control Module for Modulating Gas Furnace

Figure 21: Typical Modulating Gas Furnace Electrical Schematic with Sensor

McQuay IM 1058 27

Optional Gas Heat

Variable Furnace Controller

McQuay's furnace controller is an electronic device that delivers full control of the modulating furnace. Control includes sequencing, ignition, safety, modulation of the control valve, and the induced draft motor. Inputs to the furnace control board are an a 0-10V signal. The analog signal will modulate the burner down to 25% of full load. Safety inputs include pressure line and electrical connection from the airflow proofing switch and electrical connection from the rollout switches. Control board outputs are to the igniter board, modulating gas valve, and to the induce draft motor.

Ignition Control Module LED Diagnostics

The following LED indicators can be used to diagnose faults associated with the modulating gas furnace.

Table 14: LED Indicator and Fault Conditions

Indicator Fault Condition

Steady Off No power or control hardware fault

Indicator Fault Condition

Steady On Control fault detected or no 24 VAC power

1 Flash

2 Flashes

3 Flashes

4 Flashes

5 Flashes

6 Flashes Excessive plenum temperature 7 Flashes High limit switch is open or fuse is open

8 Flashes

Slow Flash Normal operation - no call for heat 1 Slow Flash Call for heat 2 Slow Flashes Gas on - call for heat 3 Slow Flashes Gas on - no call for heat Rapid Flash Retry

Combustion fan motor energized, pressure switch open Inducer air pressure reads above zero level when the inducer is off Flame is on when is should be off or flame is off when it should be on Gas valve is on when is should be off or gas valve is off when it should be on Safety relay is on when it should be off or safety relay is off when it should be on

Pressure switch failed to operate or modulation current is incorrect

28 McQuay IM 1058

Optional Electric Heat

Electric Heater Design

Optional Electric Heat

If the 8th digit in the model number is an “E”, the rooftop unit

Figure 22: Electric Heat Section

was furnished with a factory installed electric furnace (Example, MPS035FE). The Maverick commercial rooftop units are available with low, medium, or high heat output (see capacities in Table 15). This packaged electric heat rooftop unit is designed for outdoor non-residential installations only.

The electric heat design consists of a heating coil, DDC staging control, and all operational safeties. The safety switches include high-limit temperature switches and individual coil fusing.

The high limit switch is an automatic reset switch. It opens the control circuit and shuts the heater down when the temperature reaches 160°F. The high limit switch closes again allows the heater to run when the temperature gets to 130°F. There is a second level of protection with an auxiliary high limit switch. This switch opens up and shuts the heater down when the temperature reaches 250°F. The auxiliary switch automatically resets again at 220°F. The third level of protection is the secondary auxiliary high limit switch which shut the heater down at 285°F. This switch requires a manual reset.

Electric Heating Capacity Data

Table 15: MPS 015 – 050 Electric Heating Capacities

Ton s

* Temperature rise is calculated at nominal cfm

Nom

15 6000 4 18 950 61 9.5 36 1900 123 19.0 72 3800 246 38.0 17 6800 4 18 950 61 8.4 36 1900 123 16.7 72 3800 246 33.5 20 8000 4 36 1900 123 14.2 72 3800 246 28.5 90 4740 307 35.5 25 10,000 4 36 1900 123 11 .4 72 3800 246 22.8 90 4740 307 28.4 30 12,000 4 54 2900 184 14.2 72 3800 246 19.0 90 4800 307 23.7 35 14,000 4 54 2900 184 12.2 72 3800 246 16.3 90 4800 307 20.3 40 16,000 4 72 3800 246 14.2 90 4800 307 17.8 108 5700 369 21.3 50 20,000 4 72 3800 246 11 .4 90 4800 307 14.2 108 5700 369 17.1

cfm

Stages

Low Medium High

Min

cfm

MBh Delta T* kW

Min cfm

MBh Delta T* kW

Min cfm

MBh Delta T

Electric Heater Data

Table 16: MPS 015 – 050 Electric Heater Data (Maximum Temp. 60°F)

kW Volta ge Amps kW Volta ge Amps

18 208 50 72 208 200 18 230 45 72 230 181 18 460 23 18 575 18 72 575 72 36 208 100 36 230 90 90 230 226 36 460 45 36 575 36 90 575 90 54 208 150 54 230 136 108 575 108 54 460 68 54 575 54

McQuay IM 1058 29

72 460 90

90 208 250

90 460 113

108 460 136

Optional Modulating Hot Gas Reheat

Modulating Hot Gas Reheat

The reheat coil option comes complete with an aluminum micro channel coil and modulating hot gas valves for leaving air temperature control.

On a call for dehumidification, the unit will enable the supply to be over-cooled by the DX coil. Hot gas from the unit

Figure 23: Dual 2-Way Valve Refrigeration Schematic

condenser will be routed to an indoor coil downstream of the DX coil to reheat the air. Hot gas reheat valves (Figure 23) will control how much hot gas is routed to the indoor coil to maintain a discharge air setpoint.

30 McQuay IM 1058

Optional Modulating Hot Gas Reheat

Figure 24: Ideal for Neutral Air Ventilation Control

Dehumidification Initiation

An analog sensor is mounted in the return duct, the space, or outdoors to sense Relative Humidity. The location is selected by setting the Sensor Location value on the keypad to Return, Space, or OAT. OAT can only be selected for units with DAT control. Dehumidification is disabled when the unit is in either the Heating or Minimum DAT state. When Dehumidification is enabled, Dehumidification operation is initiated when Humidity Control is set to either Relative Humidity or Dew Point and that value rises above the appropriate setpoint by more than half its deadband. Economizer operation is disabled in the Dehumidification mode so the unit immediately transitions to Cooling if Dehumidification is initiated in Economizer state.

Dehumidification Termination

Dehumidification is terminated if the selected variable, Relative Humidity or Dew Point, drops below the appropriate humidity setpoint by more than half its deadband. Dehumidification is also terminated if cooling is disabled for any reason or the unit enters either the Heating or Minimum DAT state. For units with compressors, the number of cooling stages is reduced by one and control reverts to normal control when dehumidification is terminated in the Cooling state. Another compressor stage change could then occur after one Cooling Stage Time has elapsed.

Control & Arrangement

In conjunction with dehumidification, MHGRH is used to raise the temperature of the cooled air to a desirable value. MHGRH is comprised of a parallel coil arrangement, with both the condenser and reheat coils of the micro channel type, dual reheat valves (which operate in concert with one another) and a check valve. MHGRH components will always be installed in circuit #2.

During Dehumidification control w/ modulating Hot Gas Reheat (MHGRH) an analog signal (0-10Vdc) is controlled as described below.

• A PI Loop is used to control the HGRH valves to maintain the Discharge Air Temperature from the reheat coil.

• Compressor staging during reheat (or dehumidification) will be controlled by the Leaving DX Coil Temperature. For increased dehumidification during reheat, the standard default compressor staging range is 45 - 52°F.

• When dehumidification is active in the Cooling state, the reheat set point equals the DAT Cooling Setpoint. For DAT units, this is the normal DAT set point resulting from any reset. For Zone Control units, this set point is the result of a PI Loop based on the Control Temperature.

• Communication with the reheat control valves is accomplished by providing a 0-10Vdc signal to a pair of interface boards which in turn supply the control signal to the reheat valves (step type).

• In the Fan Only state, no sensible cooling is required, but dehumidification mode will still be enabled if the dew point or humidity sensor is not satisfied. Reheat set point varies from a maximum value (default 65°F) when the Control Temperature is at or below the heating changeover setpoint to a minimum value (default 55°F) when the Control Temperature is at or above the cooling changeover setpoint.

• Lead/Lag Arrangement w/ MHGRH (when applicable)

- Alternate staging with circuit #1 as lead will be the stan-

dard default arrangement.

- During cooling mode, circuit #1 will lead and load up

before starting circuit #2.

- During reheat mode, circuit #2 will lead and load up before

starting circuit #1.

- For reheat operation, compressor(s) in circuit #2 must be

active. If the unit is operating in the cooling mode when a call for dehumidification/reheat arises,circuit #2 will become the lead and the controller will bring on an additional stage of coolingfor dehumidification. If any compressors in circuit #1 are operating at this moment they will be switched over to compressors in circuit #2. Dehumidification operation is disabled if circuit #2 is disabled for any reason.

• In the reheat mode, the minimum position for the reheat valves is 10% (1.0 Vdc). The controller will modulate the reheat valves from this starting position.

McQuay IM 1058 31

Optional Modulating Hot Gas Reheat

• Reheat valve(s) must be at 0% (0 Vdc) position before starting the first compressor in the reheat circuit to prevent pressure spikes.

• Upon termination of dehumidification (reheat), the maximum ramp down or decay rate of the reheat control valves shall be 1% per sec (or 0.1V per sec).

• Upon termination of dehumidification (reheat), staging of compressor(s) is delayed for 1 minute after reheat capacity = 0% (0 Vdc).

Figure 25: Modulating Hot Gas Reheat Schematic

• Every 24 hours, the reheat control valves will be driven to their maximum position (10Vdc) and then returned to their normal operating position (0Vdc). If unit is operating in cooling or dehumidification (reheat) at the prescribed time it will be deferred to the next time.

• Dehumidification status can now be found under the MTIII main system menu. Reheat capacity (valve position) can also be found under the main system menu, display based on percentage (0-100%).

32 McQuay IM 1058

Optional Hot Water Heat

Hot Water Heater Design

Optional Hot Water Heat

If the 8th digit of the model number is a “W”, the rooftop unit was furnished with a factory installed hot water coil (Example: MPS035FW). The hot water coil comes with a piping vestibule for field supplied and installed control valve and piping. The coil is furnished with ODM copper connections. The Maverick commercial rooftop units are available with a low heat (one row coil) or a high heat (two row coil) configuration.

Hot water coils are not recommended for use with entering air temperatures less than 40°F (4°C). No control system can guarantee a 100% safeguard against coil freeze up. Glycol solutions or brines are the only freeze-safe media for operation of water coils at low entering air temperatures.

Figure 26: Hot Water Heating Schematic

See certified drawings for the recommended piping entrance locations. Seal all piping penetrations to prevent air and water leakage.

Note: Factory installed piping is copper. Dissimilar metal

within the plumbing system can cause galvanic corrosion. To avoid corrosion, provide proper di-electric

fittings as well as appropriate water treatment.

CAUTION

Coil freeze possible. Can damage equipment.

Follow instructions for mixing antifreeze solution. Some products have higher freeze points in natural state than when mixed with water. The freezing of coils is not the responsibility of McQuay International.

McQuay IM 1058 33

Optional Hot Water Heat

Hot Water Pressure Drop Data

Figure 27: MPS 015 – 017 Low and High Heat

Figure 28: MPS 020 – 025 Low and High Heat

34 McQuay IM 1058

Figure 29: MPS 030 – 035 Low and High Heat

Optional Hot Water Heat

Figure 30: MPS 040 – 050 Low and High Heat

McQuay IM 1058 35

Unit Options

Economizer Enthalpy Control

The economizer can be ordered with the optional differential enthalpy control. With this option a solid-state humidity and temperature sensing device is located in the return and outdoor airstreams. These devices are labeled RAE and OAE respectively. When the outdoor enthalpy is lower than the return air enthalpy, the economizer operation will be initiated. If the outdoor air enthalpy is higher than the return air, the outdoor air damper position will be at the minimum setpoint. See OM 920 for further information on the economizer operation.

External Time Clock

You can use an external time clock as an alternative to (or in addition to) the MicroTech III controller’s internal scheduling function. The external timing mechanism is set up to open and close the circuit between field terminals 101 and 102. When the circuit is open, power is not supplied to binary input ID1. This is the normal condition where the controller follows the programmable internal schedule. When the circuit is closed, power is fed to ID1. The MicroTech III controller responds by placing the unit in the occupied mode, overriding any set internal schedule.

Exhaust Fan Option

Economizer units may include exhaust fan options. For units with CAV applications, the exhaust fans can be ordered as staged control or they may be ordered with building pressure control. The building pressure control option has a VFD that runs the exhaust fan motors and is controlled by the static pressure sensor number 2 (SPS2). Refer to OM 920 for setting up the unit controller with these two options. The units are only available with building pressure control on VAV units.

The exhaust fan motors are permanently lubricated and do not require any additional periodic lubrication.

Proof-of-Airflow and Dirty Filter Switch

The proof-of-airflow switch (PC7) and the dirty filter switch (PC5) are supplied on all CAV units. The tubing is installed to the switches per Figure 31. The proof of airflow switches senses the pressure difference between the positive pressure in the supply air fan compartment and the suction pressure on the leaving air side of the filters. The differential pressure is factory set at 0.25" for this switch. The dirty filter switch

senses the pressure difference across the filter; from the entering air side of the filter to the leaving air side of the filters. The switch is factory set at 1.0". When the pressure difference across the filters is sensed at this value, the dirty filter alarm will appear on the DDC controller.

Figure 31: Pressure Tubing Diagram

TO ENTERING

AIR SIDE OF

THE FILTERS

TO LEAVING AIR SIDE OF

THE FILTERS

TO SUPPLY

FAN PLENUM

PC5

HI LO

PC7

DHL

All VAV units also have the PC7 and PC5 switches as standard (see Figure 31). These switches are tied into the Duct High Limit switch (DHL) as shown in Figure 31.

The DHL is factory set at 4.0". When this differential pressure is sensed the normally closed contacts will open on the switch giving the DHL alarm at the unit controller.

Duct High Pressure Limit

The duct high pressure limit control (DHL) is provided on all VAV units. The DHL protects the duct work, terminal boxes, and the unit from over pressurization, which could be caused by, for example, tripped fire dampers or control failure.

The DHL control opens when the discharge plenum pressure rises to 3.5" wc (872 Pa). This setting should be correct for most applications and should not be adjusted.

If the DHL switch opens, digital input ID9 on the Unit Control Board will be de-energized. The MicroTech III controller then shuts down the unit and enters the Off-Alarm state. The alarm must be manually cleared before the unit can start again. Refer to the operation manual supplied with your unit for more information on clearing alarms (refer to OM 920).

36 McQuay IM 1058

Unit Options

460V LINE460V LINE

VOLTAGE PRI.VOLTAGE PRI.

Convenience Receptacle (Field Powered)

A Ground Fault Circuit Interrupter (GFCI) convenience receptacle is provided in the main control box on all units. To

use this receptacle, connect a separate field-supplied 115 V power wiring circuit to the outlet.

Figure 32: Unit Powered GFCI Receptacle Schematic

Convenience Receptacle (Unit Powered)

A Ground Fault Circuit Interrupter (GFCI) convenience receptacle is provided in the main control box on all units. The receptacle shall be powered by a factory installed and wired 120V, 20 amp power supply. The power supply shall be wired to the line side of the unit's main disconnect, so the receptacle is powered when the main unit disconnect is off. This option shall include a GFI receptacle, transformer, and a branch circuit disconnect. The electrical circuit shall be complete with primary and secondary overload protection. See Figure 32 for a branch circuit diagram.

McQuay IM 1058 37

Wiring Diagrams

Figure 33: VAV Power

38 McQuay IM 1058

Wiring Diagrams

McQuay IM 1058 39

Wiring Diagrams

Figure 34: VAV Control—Inputs

40 McQuay IM 1058

Wiring Diagrams

McQuay IM 1058 41

Wiring Diagrams

Figure 35: VAV Control—Outputs (Staged Gas Heat)

42 McQuay IM 1058

Wiring Diagrams

McQuay IM 1058 43

Wiring Diagrams

Figure 36: CAV Power

44 McQuay IM 1058

Wiring Diagrams

McQuay IM 1058 45

Wiring Diagrams

Figure 37: CAV Control—Inputs

46 McQuay IM 1058

Wiring Diagrams

McQuay IM 1058 47

Wiring Diagrams

Figure 38: CAV Control—Outputs (Staged Gas Heat)

Figure 39: VAV/CAV Control—Outputs (Modulating Gas Heat)

48 McQuay IM 1058

Figure 40: Electric Heat Option Power

Figure 41: Electric Heat Option—Outputs

Wiring Diagrams

McQuay IM 1058 49

Sequence of Operation

Any Othe r Stat e

Fan Only

Minimum DAT

Mechanical

Coolling

Start Up

Recirculation

Sequence of Operation

Operating States

The transition from any operating state to another is graphically represented in Figure 42.

Figure 42: State Diagram

Off

Economize

Heating

Fan Only

The outside air damper will modulate to the minimum position and based upon the sensor inputs, the unit will go into one of the four running states - “Heating,” “Cooling,” “Economizing,” or “Minimum DAT.” If the control temperature is between its setpoint and its dead band, the unit will remain in the “Fan Only” state.

Heating

The unit's heating mode of operation is controlled by the control temperature and the heating setpoint temperature. The unit goes into the heating mode of operation by analyzing the control temperature.

The control temperature can be either the return temperature or the space temperature.

The return temperature is typically used for VAV units and the space temperature is typically used for CAV units.

The unit goes into the heating mode of operation when the control temperature (return or space temperature) is below the heating setpoint by more than ½ the deadband.

Example - If the heating setpoint is 68.0°F and the deadband is

1.0°F, the unit will not go into the heating mode of operation

until the control temperature reaches 67.4°F.

Start Up

With a “start up” command from the “Off” State the unit will default into the “Start Up” state of operation for 3 minutes. During this time, the fan is off.

Recirculation

Next, the unit will transition into the “Recirculation” state of operation for another 3 minutes. During this time, the outside air damper will close and the fan will turn on, thereby mixing the air in the ductwork and the space.

When this takes place, the heating mode of operation will begin and the 1st stage of heating operation will start.

The next stage, up or down, will take place after 4 minutes. This “4 minutes” is called the stage timer. The gas or electric heat module will continue to stage up as long as the control temperature is below the heating setpoint by more than ½ the heating setpoint deadband. The unit will stage down if the maximum discharge air temperature of 120°F is reached. Gas units with one gas valve have 2 stages of heating and units with two gas valves have 4 stages of heating.

Minimum DAT

This control mode is designed to temper the air in the ductwork when in heating mode. When the unit is in the “Fan Only” state and the Discharge Air Temperature is less than the minimum discharge air temperature limit, “Minimum DAT” control is initiated. The unit will turn on minimum heat until the discharge air temperature exceeds the limit.

50 McQuay IM 1058

Sequence of Operation

Mechanical Cooling

Constant Volume (Space Comfort Controller)

The control temperature for a CAV unit is typically the space temperature. A space temperature sensor must be field installed into the occupied space and connected to the unit controller.

The unit goes into the cooling mode of operation when the control temperature (space temperature) is above the cooling setpoint by more than ½ the deadband.

Example - the cooling setpoint is set to 70.0°F and the deadband is 1.0°F, the unit will not go into the cooling mode of operation until the space sensor reaches 70.6°F.

When this takes place, the cooling mode of operation will begin and the 1st stage of compressor operation will start.

The unit controller will turn on the next stage of compressor operation, or turn off a stage of compressor operation, to maintain the cooling setpoint temperature within the deadband. When a compressor stage turns on, the next compressor stage, up or down, will not take place for the next 4 minutes. This “4 minutes” is called the stage time. Reference the “Cooling Setup” menu for the adjustable stage time value.

When a cooling stage is initiated no further operation will take place within the stage timer limit. In the above example, the unit will stage down or turn off the cooling mode of operation when the cooling setpoint reaches 69.4°F.

Variable Air Volume (Discharge Air Controller)

The unit's cooling mode of operation is controlled by the control temperature, the change-over temperature, and the discharge air temperature. The unit goes into the cooling mode of operation by analyzing the control temperature. The control temperature for a VAV system is the return temperature.

The unit goes into the cooling mode of operation when the control temperature (return temperature) is above the changeover setpoint by more than ½ the deadband.

Example - If the change over temperature is 70.0°F and the deadband is 1.0°F, the unit will not go into the cooling mode of operation until the return temperature reaches 70.6°F.

When this takes place, the cooling mode of operation will begin and the 1st stage of compressor operation will start.

The unit controller will turn on the next stage of compressor operation, or turn off a stage of compressor operation, to maintain the discharge air temperature setpoint within the deadband. When a compressor stage turns on, the next compressor stage up or down will not take place for the next 4 minutes. This “4 minutes” is called the stage timer.

When a cooling stage is initiated no further operation will take place within the stage timer limit. Reference the Cooling Setup menu for the adjustable stage time value. In the above example, the unit will stage down or turn off the cooling mode of operation when the return temperature reaches 69.4°F.

Economizer

When the economizer is enabled, the outside air temperature is below the changeover setpoint, and the differential enthalpy switch (if installed) is made, the economizer becomes the first stage of cooling. It will modulate to control to either the discharge air temperature (VAV) or space temperature (CV).

Every 4 minutes, the unit can then either add mechanical cooling if the economizer is at 100% open, continue economizing, or if the control temperature is satisfied, return to minimum position and transition back to “Fan Only” mode.

If the enthalpy switch breaks or the outside air warms, the unit will exit economizing and continue to mechanically cool while returning to the minimum position for ventilation.

McQuay IM 1058 51

Check, Test, and Start Procedures

Pre-Start of Unit

All units are completely run tested at the factory to promote proper operation in the field. However, to ensure proper operation once the unit is installed, the following check, test, and start procedures must be performed to properly start the unit. To obtain full warranty coverage, complete and sign the check, test, and start form supplied with the unit and return it to McQuay International.

WARNING

Electric shock and moving machinery hazard. Can cause severe equipment damage, personal injury, or death.

Disconnect and tag out all electrical power before servicing this equipment.

All start-up and service work must be performed only by trained, experienced technicians familiar with the hazards of working on this type of equipment.

Read and follow this manual: “MicroTech III Unit Controller” (OM 920) before operating or servicing.

Bond the equipment frame to the building electrical ground through grounding terminal or other approved means.

A representative of the owner or the operator of the equipment should be present during start-up to receive instructions in the operation, care, and maintenance of the unit.

Servicing Control Panel Components

WARNING

Hazardous voltage. May cause severe injury or death.

Disconnect electric power before servicing equipment.

Before Start-Up

1 Remove shipping bolt form fan spring.

2 Verify that the unit is completely and properly installed

with ductwork connected.

3 Verify that all construction debris is removed, and that the

filters are clean.

4 Verify that all electrical work is complete and properly

terminated.

5 Verify that all electrical connections in the unit control

panel are tight, and that the proper voltage is connected.

6 Verify all nameplate electrical data is compatible with the

power supply.

7 Verify the phase voltage imbalance is no greater than 2%.

8 Verify that gas piping is complete and leak tight.

9 Verify that the shutoff cock is installed ahead of the

furnace, and that all air has been bled from the gas lines.

10 Verify installation of gas flue and outside air vents.

11 Manually rotate all fans and verify that they rotate freely.

12 Verify that the belts are tight and the sheaves are aligned.

13 Verify that all setscrews and fasteners on the fan assemblies

are still tight. “See “Setscrews” on page 59.”

14 Verify that the evaporator condensate drain is trapped and

that the drain pan is level.

15 If unit is curb mounted, verify that the curb is properly

flashed to prevent water leakage.

16 Review the equipment and service literature, the sequences

of operation, and the wiring diagrams to become familiar with the functions and purposes of the controls and devices.

17 Determine which optional controls are included with the

unit.

Power-Up

1 Close the unit disconnect switch.

2 Power should now be supplied to the control panel.

Fan Start-Up

1 Remove shipping bolt from fan spring if this has not

already been done.

1 Verify fan spring adjustment and that the fan assembly is

level. Adjust as necessary.

2 Verify all duct isolation dampers are open.

3 Place the unit into the “Fan Only” mode through the

keypad.

4 The controller should enter the “Startup Initial” operating

state. If the fan does not run, check the manual motor protectors or that the circuit breakers have not tripped.

5 Verify the rotation is correct.

Economizer Start-Up

1 Check whether the outdoor air is suitable for free cooling.

2 At the keypad, set the cooling setpoint low enough so the

controller calls for cooling.

3 Place the unit into cooling mode through the keypad menu.

4 Observe the outdoor air dampers:

a If the outdoor enthalpy is low, the control algorithm

should start to modulate the dampers open to maintain the discharge air setpoint.

b If the outdoor enthalpy is high, the dampers should

maintain their minimum position.

Note: It may not be possible to check the economizer

operation in both low and high enthalpy states on the same day. If this is the case, repeat this procedure on another day when the opposite outdoor air enthalpy conditions exist.

52 McQuay IM 1058

Compressor Start-Up

1.21"

Fan Blade

Orifice

With the supply fan operational, prepare for compressor operation.

CAUTION

Low ambient temperature hazard. Can cause compressor damage. Do not attempt to start up and check out the

refrigeration system when the outdoor air temperature is below 20°F.

1 Connect service gauges and verify that the unit has not lost

its refrigerant charge.

2 Verify that the crankcase heaters are operating. These

should operate for at least 24 hours before starting the compressors.

3 Verify that the condenser fan blades are positioned properly

(see Figure 43) and that the screws are tight. The fan blade must be correctly positioned within its orifice for proper airflow across the condenser coils.

4 Check the fan rotation.

Figure 43: Condenser Fan Blade Positioning

Scroll Compressor Rotational Direction

Scroll compressors only compress in one rotational direction. Three-phase compressors rotate in either direction depending upon phasing of the power to L1, L2, and L3. Since there is a 50/50 chance of connecting power to cause rotation in the reverse direction, verify that the compressor rotates in the proper direction after the system is installed. If the compressor is rotating properly, suction pressure drops and discharge pressure rises when the compressor is energized. If the compressor is rotating in reverse, the sound level is louder and current draw is reduced substantially. After several minutes of operation, the compressor’s internal protector trips.

All three-phase compressors are wired the same internally. Therefore, once the correct phasing is determined for a specific system or installation, connecting properly phased power leads to the same terminals should maintain proper rotation direction.

Perform the Following Procedure:

At the keypad, set the cooling setpoint low enough so that the controller will call for cooling.

Check, Test, and Start Procedures

NOTICE

Venting refrigerant to atmosphere is not allowed per most local laws and/or codes.

2 Verify that compressor #1 starts. If the compressor motor

hums but does not run, verify that it is getting three-phase power.

3 The compressor should operate continuously while there is

a call for cooling. If the compressor cycles on and off on its low pressure switch, perform the following:

a Verify that the circuit is not short of refrigerant.

b Check for low airflow across the evaporator coil.

c Check for clogged filters.

d Check for restricted ductwork.

e Check for very low temperature return air entering the

unit.

f Verify that the liquid line components, expansion valve,

and distributor tubes are feeding the evaporator coil.

g Verify that all air handling section panels are closed.

4 Verify that the condenser fans are cycling and rotating

properly (blowing air upward). When the compressor starts, at least one condenser fan should also start.

5 Check the oil level in the compressor sightglass. If low oil

is observed, it is possible that liquid refrigerant is returning to the compressor. Check the suction superheat, see “Expansion Valve Superheat Adjustment” below. It should be between 10°F (5.5°C) and 13°F (7.2°C). See “Expansion Valve Superheat Adjustment” below.

6 Verify that the condenser refrigerant subcooling at full

capacity is between 13°F and 20°F.

Checking Subcooling

Following are recommendations for checking subcooling:

1 Run unit until it reaches steady state. Close the unit section

doors. Running the unit with its doors open will affect system operation.

2 Measure the discharge gas pressure at the compressor

discharge gauge port with an accurate gauge. Use this pressure to determine the saturation temperature of the refrigerant.

3 Measure liquid temperature accurately by attaching a

thermocouple to the liquid line tube leaving the condenser coil. Insulate the tube and thermocouple for more accurate results.

4 Subtract the measured liquid temperature from the

saturation temperature to determine the subcooling.

5 As a general rule, high subcooling indicates that the circuit

is low on charge. Low subcooling generally indicates that the circuit has too much charge.

McQuay IM 1058 53

Check, Test, and Start Procedures

Bearing

Motor

Must be parallel

Fixed Pitch Sheave

Center lines must coincide

Must be parallel

Expansion Valve Superheat Adjustment

It is very important that the expansion valve superheat setting be adjusted to be between 10°F (5.5°C) and 13°F (7.2°C). Insufficient superheat will cause liquid floodback to the compressor which may result in slugging. Excessive superheat will reduce system capacity and shorten compressor life.

Turn the adjustment stem clockwise to increase superheat. Not exceeding one turn, adjust the stem and then observe the superheat. Allow up to 30 minutes for the system to rebalance at the final superheat setting.

Checking Superheat

Following are recommendations for checking superheat:

1 Close the unit section doors. Running the unit with its

doors open will affect expansion valve and system operation considerably.

2 Check the pressure and temperature at the suction gauge

port.

Sheave Alignment

1 Verify both motor and fan sheaves are in alignment and the

shafts are parallel. The center line of the motor sheave must be in line with the center line of the fan sheave. See Figure 44.

2 Verify that all setscrews are torqued to the values shown in

Table 18 on page 59 before starting drive. Check setscrew torque and belt tension after 24 hours of service.

Figure 44: Sheave Alignment (Adjustable Shown)

Drive Belt Tension Adjustment

1 The ideal tension is the lowest tension at which the belt will

not slip under peak load conditions. Over tensioning shortens belt and bearing life.

2 Check tension frequently during the first 24–48 hours of

operation.

3 Keep belts free from foreign material which may cause

slippage.

4 Make V-drive inspection on a periodic basis. Adjust tension

if the belt is slipping. Do not apply belt dressing. This may damage the belt and cause early failure.

Air Balancing

The following should be performed by a qualified air balancing technician:

WARNING

Moving machinery hazard. Can cause severe personal injury or death. Do not use a mechanically driven tachometer

to measure the speed of return fans on this fan arrangement. Use a strobe tachometer.

1 Check the operating balance with the economizer dampers

positioned for both full outdoor air and minimum outdoor air.

2 Verify that the total airflow will never be less than that

required for operation of the electric heaters or gas furnace.

3 When the final drive adjustments or changes are complete,

check the current draw of the supply fan motors. The amperage must not exceed the service factor stamped on

the motor nameplate.

WARNING

Rotating parts can cause severe personal injury or death.

Replace all belt/fan guards that are removed for service.

54 McQuay IM 1058

Final Control Settings

Controller Settings for Normal Operation

When all start-up procedures are completed, set the controls and program the MicroTech III controller for normal operation. Use the following list as a guide; some items may not apply to your unit.

1 Set the heating and cooling parameters as required for

normal unit operation:

a Temperature \ Zone Cooling \

b Temperature \ Zone Heating \

c Temperature \ Discharge Cooling \

2 Set the low ambient compressor lockout setpoint as

required. Do not set it below 20°F.

3 Set the high ambient heat lockout temperature setpoint.

4 Set the alarm limits as required.

5 Set the duct static pressure control parameters as required.

Final Control Settings

6 Set the building static pressure control parameters as

required.

7 Set the economizer control parameters as required.

8 Set the date and time in keypad menu.

9 Set the operating schedule as required using keypad menus.

Note: Unit operation may also be controlled by the building

automation system.

Maintaining Control Parameter Records

McQuay recommends that the MicroTech III controller’s setpoints and parameters be recorded and saved for future reference. If the microprocessor control board requires replacement, this record facilitates entering the unit’s proper data.

McQuay IM 1058 55

Maintenance

Performing Service Maintenance

Installation and maintenance must be performed only by qualified personnel who are experienced with this type of

equipment and familiar with local codes and regulations.

WARNING

Moving machinery and electrical power hazards. May cause severe personal injury or death. Disconnect and lock

off all power before servicing equipment.

CAUTION

Sharp edges are inherent to sheet metal parts, screws, clips, and similar items. May cause personal injury.

Exercise caution when servicing equipment.

Servicing Control Panel Components

Disconnect all electric power to the unit when servicing control panel components. Before servicing, always inspect units for multiple disconnects to ensure all power is removed

from the control panel and its components.

WARNING

Hazardous voltage. May cause severe injury or death.

Disconnect electric power before servicing equipment. More than one disconnect may be required to de-energize the unit.

• Check the power and control voltages.

• Check the running amperage of all motors.

• Check all operating temperatures and pressures.

• Check and adjust all temperature and pressure controls as

needed.

• Check and adjust all damper linkages as needed.

• Check the operation of all safety controls.

• Check the condenser fans and tighten their setscrews.

All-Aluminum Condenser Coils

The condenser coils are an all-aluminum design including the connections, micro-channels, fins (an oven brazing process brazes the fins to the micro-channel flat tube), and headers (Figure 45), which eliminates the possibility of corrosion normally found between dissimilar metals of standard coils.

During the condensing process, refrigerant in the coil passes through the micro-channel flat tubes, resulting in higher efficiency heat transfer from the refrigerant to the airstream.

Figure 45: Micro-Channel Coil Cross-Section

Planned Maintenance

Preventive maintenance is the best way to avoid unnecessary expense and inconvenience. Have this system inspected at regular intervals by a qualified service technician. The required frequency of inspections depends upon the total operating time and the indoor and outdoor environmental conditions. Routine maintenance should cover the following items:

• Tighten all belts, wire connections, and setscrews.

• Clean the evaporator and condenser coils mechanically or

with cold water, if necessary. Usually any fouling is only matted on the entering air face of the coil and can be removed by brushing or vacuuming.

• Lubricate the motor and fan shaft bearings.

• Align or replace the belts as required.

• Clean or replace the filters as required.

Note: A partially full sight glass is not uncommon at part load

conditions. A varying amount of bubbles may be noticeable in the sightglass, which is normal.

• Check for proper superheat.

• Check for blockage of the condensate drain. Clean the

condensate pan as needed.

56 McQuay IM 1058

Maintenance

Connecting the Condenser Coil to Copper Tubing

Figure 46 shows the aluminum condenser coil connection to the copper tubing in the unit. Because of the low melting point of aluminum (1220°F compared to 1984°F for copper), this brazed joint is performed with a low temperature brazing

process.

CAUTION

Potential equipment damage. If a standard copper brazing process is performed at this joint, the process will damage the aluminum connection. If a condenser coil ever needs to

be replaced, the copper aluminum joint repair should be done with a ProBraze™ repair kit manufactured by Omni Technologies Corporation. A non-corrosive flux must also be used. The brazing temperature should be between 850°F – 900°F.

Figure 46: Aluminum/Copper Connection

• Provide proper drainage around the unit to prevent flooding of the equipment.

• Provide adequate protection from vandalism, mechanical contact, etc.

• Make sure all doors are securely closed and all latches closed.

• Units should be fitted with covers over the supply and return air openings.

Preparation for Storage

Supply Fans

1 Remove the drive belts, tag them with the fan name and

unit serial number, and store them in a conditioned space out of direct sunlight.

2 Once every two weeks, rotate the fan and motor shafts.

Mark the shaft positions first to make sure they stop in a different position.

3 Depending on local climate conditions, condensate may

collect on components inside the units. To prevent surface rust and discoloration, spray all bare metal parts with a rust preventive compound. Pay close attention to fan shafts, sheaves, bearings, and bearing supports.

Unit Storage

Location

The Maverick II is an outdoor unit. However, the construction schedule may dictate storage either on the ground or in its final position at the site. If the unit is stored on the ground, additional precautions should be taken as follows:

• Make sure that the unit is well supported along the length of the base rail.

• Make sure that the unit is level (no twists or uneven ground surface).

Cabinet Sections

Once a month, open a door on each section and verify that no moisture or debris is accumulating in the unit.

Control Compartment

1 McQuay International recommends that the electronic

control equipment in the unit be stored in a 5% to 95% RH (non-condensing) environment.

2 It may be necessary to put a heat source (light bulb) in the

main control panel to prevent the accumulation of atmospheric condensate within the panel. The location and wattage of the heat source is dependent on local environmental conditions.

3 Check the control compartment every two weeks to

confirm that the heat source is functional and is adequate for current conditions.

Restart

After extended storage, perform a complete start up. Inevitable accumulations of dirt, insect nests, etc. can contribute to problems if not cleaned out thoroughly prior to start up. In addition, thermal cycling tends to loosen mechanical and electrical connections. Following the startup procedure helps discover these and other issues that may have developed during the storage interval.

McQuay IM 1058 57

Maintenance

Bearing Lubrication

CAUTION

Bearing overheating potential. Can damage the equipment.

Do not overlubricate bearings. Use only a high grade mineral grease with a 200°F safe operating temperature.

Motor Bearings

Supply Fans

Supply fan motors should have grease added after every 2000 hours of operation. Use one of the greases shown in Table 17. Using the following procedure, relubricate the bearings while the motor is warm, but not running.

1 Remove and clean upper and lower grease plugs.

2 Insert a grease fitting into the upper hole and add a small

amount of clean grease with a low pressure gun.

3 Install the lower grease plug.

4 Run the motor for five minutes before installing the upper

grease plug.

Condenser Fan and Exhaust Fan

The condenser fan and exhaust fan motors are permanently lubricated and require no periodic lubrication.

Fan Shaft Bearings

Relubricate fan shaft bearings periodically. Relubricate according to the schedule on the fan housing. If the bearings are exposed to wet conditions, wide temperature variations, or other severe atmospheric conditions, relubricate more frequently. Use one of the greases shown in Table 17.

Table 17: Recommended Greases

Manufacturer Product Name Tem p. Ra nge (° F)

Texaco Lubricants Co. Premium RB -30 to 300

Mobil Oil Corporation Mobilith AW2 -40 to 325

Shell Oil Company Alvania No. 2 -20 to 240

Vibration Levels

Each unit as shipped is trim balanced to operate smoothly. To provide satisfactory operation after shipping and installation, use accepted industry guidelines for field balancing fans.

Note: Excessive vibration from any cause contributes to

premature fan and motor bearing failure. Monitor overall vibration levels every six months of operation. An increase in levels is an indication of potential trouble.

Vibration Causes

1 Wheel imbalance.

a Dirt or debris on wheel blades.

b Loose setscrews in wheel hub or bearing-to-shaft.

c Wheel distorted from overspeed.

2 Bent shaft.

3 Faulty drive.

a Bad V-belts; lumpy, or mismatched.

b Belt tension too tight or too loose.

4 Bad bearings or loose bearing hold-down bolts.

5 Motor imbalance.

6 Fan section not supported evenly on foundation.

While the bearing is at normal operating temperatures, rotate the fan by hand and add only enough grease to purge the seals. The seals bleed slightly when this occurs. Do not overlubricate.

Periodic Service and Maintenance

1 Check all moving parts for wear every six months.

2 Check bearing collar, sheave, and wheel hub setscrews,

sheave capscrews, and bearing hold-down bolts for tightness every six months.

58 McQuay IM 1058

Maintenance

W h e e l

F u n n e l

Setscrews

Setscrews are used to lock bearings, sheaves, locking collars, and fan wheels to their shafts. They must be checked periodically to see that they have not loosened. If this is not done, severe equipment damage could occur.

Refer to the values in Table 18 and check the tightness of all setscrews with a torque wrench.

Table 18: Setscrew Minimum Torque Specifications

Setscrew Diameter (in.) Minimum Torque (ft.lb)

1/4 5.5

5/16 10.5

3/8 19.0

7/16 29.0

1/2 42.0 5/8 92.0

Supply Fan Wheel-to-Funnel Alignment

The fan wheel-to-funnel alignment must be as shown in Figure 47 to obtain proper air delivery and operating clearance. If necessary, adjustments are made as follows:

1 Verify that the fan shaft has not moved in its bearings.

2 Loosen the fan hub setscrews and move the wheel(s) along

the shaft as necessary to obtain the correct dimension shown in Table 19.

3 Retighten the setscrews to the torque specification given in

Table 18 on page 59. Tighten the setscrews over the keyway first; tighten those at 90 degrees to the keyway last.

4 Verify that the radial clearance around the fan is uniform.

Figure 47: SWSI Airfoil Wheel-to-Funnel Alignment

Refrigerant Charge

The unit nameplate references proper charge for each refrigerant circuit in case a full charge must be added to the unit.

CAUTION

Severe loss of charge may occur if the high refrigerant pressure switch is replaced before reclaiming the refrigerant. Replace pressure switch after reclaiming

refrigerant.

Servicing Refrigerant Sensors or Switches

The Maverick II includes the following refrigerant sensors or switches.

1 Low refrigerant pressure sensing, operating switch,

automatic reset.

a Disables associated compressors on a drop in suction

pressure to approximately 35 psig.

b Enables associated compressors on a rise in suction

pressure to approximately 60 psig.

2 High refrigerant pressure, protective switch, manual reset

at keypad.

The low pressure switch senses refrigerant pressure through shrader fittings that contain cores. The cores are stop valves that do not allow refrigerant to flow through the Shrader unless the device is in place. Therefore, the low pressure switch can be replaced without reclaiming the refrigerant.

The Shrader that serves the high pressure switch does not contain a core in order to maximize the functionality of the safety. Therefore it cannot be replaced unless the refrigerant has already been reclaimed.

Servicing Optional Electric Heater

WARNING

Hazardous voltage. May cause severe injury or death.

Disconnect electric power before servicing equipment. More than one disconnect may be required to de-energize the unit.

Table 19: SWSI Airfoil Wheel-to-Funnel Relationship

Wheel-to-Funnel Relationship (in inches)

Wheel Diameter A

15 0.44 18 0.44 20 0.44 22 0.44 24 0.44 30 0.56

McQuay IM 1058 59

If the electric heater is not operating properly, a qualified electrician should perform the following to check if the heater is damaged:

1 Measure continuity through all fuses.

2 Check that all electrical connections are tight. Look for

signs of arcing.

3 Check the resistance to ground for each circuit. It should be

infinite.

4 Check the resistance phase to phase for each circuit.

5 Check all contactors.

Service and Warranty Procedure

Service and Warranty Proc edure

Replacement Parts

When contacting McQuay for service or replacement parts, provide the model number, serial number, and unit part number of the unit as stamped on the serial plate attached to the unit. For questions regarding wiring diagrams, provide the number on the specific diagram. If replacement parts are required, include the date of unit installation, the date of failure, an explanation of the malfunction, and a description of the replacement parts required.

Scroll Compressor

All McQuay Rooftop products include a first-year parts only warranty. The warranty period extends 12 months from startup or 18 months from date of shipment, whichever comes first. Labor to install these parts is not included with this warranty. Compressors are considered a part and are included in this standard warranty.

All Compressors

Replacement compressors for McQuay Rooftop Units can be obtained from the McQuay Service Parts department.

The decision to replace the failed portion of the compressor tandem, as opposed to replacing the entire tandem, must be decided based on the following.

1 In warranty: Warranty only covers replacement of the failed

portion of the tandem.

2 Out of warranty: The customer decides whether to replace

the entire tandem or just a portion.

3 Some equipment may include the extended 2nd - 5th year

compressor warranty option.

Order the replacement compressor through the McQuay Parts Department (Minneapolis).

1 Contact the McQuay Parts Department for compressor

availability.

2 Send a completed parts order form to the McQuay Parts

Department.

3 The Parts Department processes the order and the

compressors are shipped from our Dayton, OH warehouse via ground transportation. If next-day air is required, indicate this on the parts order form and a freight charge will be billed to your account. Air freight costs are not covered under the McQuay warranty.

4 After the failed compressor is replaced, return it to McQuay

International with a Return Goods Tag attached, which you will receive in the mail. It must be attached to the compressor. The Return Goods Tag has instructions on where to send the compressor. If the compressor is not returned, you will be billed for the replacement compressor.

5 Consideration may be given at this time to a compressor

teardown analysis, depending on the history of failures.

In-Warranty Return Material Procedure

Material other than compressors may not be returned except by permission of authorized factory service personnel of McQuay International at Minneapolis, Minnesota.

A “return goods” tag will be sent to be included with the returned material. Enter the information as called for on the tag in order to expedite handling at out factories and issuance of credits. All parts shall be returned to the factory designated on the return goods tag, transportation charges prepaid.

The return of the part does not constitute an order for replacement. A purchase order for the replacement part must be entered through your nearest McQuay representative. The order should include the component's part number and description and the model and serial numbers of the unit involved.

If it is determined that the failure of the returned part is due to faulty material or workmanship within the standard warranty period, credit will be issued on the customer's purchase order.

60 McQuay IM 1058

Commercial Rooftop Equipment Warranty Registration Form

Commercial Rooftop Equipment Warranty

Commercial Rooftop Equipment Warranty Registration Form

To comply with the terms of McQuay Warranty, complete and return this form within 10 days to McQuay, Warranty Department

Check, test, and start procedure for Maverick II roof mounted air conditioners.

Job Name:

Installation address: __________________________________________________________________________________________________

City: _____________________________________________________________________________ State:___________________________

Purchasing contractor: ________________________________________________________________________________________________

City:______________________________________________________________________________ State:___________________________

Name of person doing start-up (print) ____________________________________________________________________________________

Company name _____________________________________________________________________________________

Address ___________________________________________________________________________________________

City/State/Zip _______________________________________________________________________________________

Unit model number: _________________________________________________ Unit serial number: ________________________________

Compressor 1 model number: ________________________________________ Serial number:____________________________________

Compressor 2 model number: ________________________________________ Serial number:____________________________________

Compressor 3 model number: ________________________________________ Serial number:____________________________________

Compressor 4 model number: ________________________________________ Serial number:____________________________________

Circle Yes or No. If not applicable to the type of unit, circle N/A.

I. INITIAL CHECK

A. Is any shipping damage visible?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

B. Are fan drives properly aligned and belts properly adjusted?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

C. Tightened all setscrews on pulleys, bearings and fans?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

D. Have the hold-down bolts been backed off on spring mounted fan isolators? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

E. Do fans turn freely? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

F. Has the discharge static pressure reference line been properly located within the building? Yes No N/A

G. Electrical service corresponds to unit nameplate? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

Vol ts Hertz Phase

H. Is the main disconnect adequately fused and are fuses installed?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

I. Are crankcase heaters operating, and have they been operating 24 hours prior to start-up? . . . . . . . . . . . . . . . . . . . . Yes No N/A

J. Are all electrical power connections tight? (Check compressor electrical box.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

K. Is the condensate drain trapped? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

II. FAN DATA

A. Check rotation of supply fan? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

B. Voltage at supply fan motor: 1–2_________ V 2–3 _________ V 1–3 _________ V

C. Supply fan motor amp draw per phase: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L1 L2 L3

D. Fuse sizes: ___________________________________________________________________

E. What is the supply fan rpm?

F. Record supply static pressure at unit:_______________ inches of H20

G. Record return static pressure at unit (with outside air dampers closed) ______________ inches of H20

III. START-UP COMPRESSOR OPERATION

A. Do compressors have holding charges?

Circuit #1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

Circuit #2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

B. Are compressors rotating in the right direction? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

C. Do condenser fans rotate in the right direction? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

D. Ambient temperature ______________________ °F

IV. PERFORMANCE DATA

A. Compressor voltage across each phase: 1–2 _________ V 2–3 _________ V 1–3 ________ V

B. Compressor amperage of fully loaded compressor:

Compressor #1 Phase 1________ Phase 2 ________ Phase 3 _______

Compressor #2 Phase 1________ Phase 2 ________ Phase 3 _______

Compressor #3 Phase 1________ Phase 2 ________ Phase 3 _______

Compressor #4 Phase 1________ Phase 2 ________ Phase 3 _______

McQuay G.O. No.:

McQuay IM 1058 61

Commercial Rooftop Equipment Warranty Registration Form

Warranty Registration Form (continued)

C. Low pressure cut-out: Circuit 1 ___________ psig Circuit 2 __________ psig

Low pressure cut-in: Circuit 1 ___________ psig Circuit 2 __________ psig

D. High pressure cut-out: Circuit 1 ___________ psig Circuit 2 __________ psig

E. Discharge pressure, one compressor: Circuit 1 __________ psig Circuit 2___________ psig

Discharge pressure, fully loaded, 2–3 compressors: Circuit 1 __________ psig Circuit 2___________ psig

F. Suction pressure, one compressor: Circuit 1 __________ psig Circuit 2___________ psig

Suction pressure, fully loaded, 2–3 compressors: Circuit 1 __________ psig Circuit 2___________ psig

Liquid press, fully loaded, 2–3 compressors: Circuit 1 __________ psig Circuit 2___________ psig

Liquid temperature, fully loaded, 2–3 compressors: Circuit 1 __________ psig Circuit 2___________ psig

G. System oil pressure (oil pressure-suction-net oil pressure):

(on four-compressor units, indicate for each compressor)

H. Suction line temperature: ____________ °F ____________°F

I. Superheat: ____________ °F ____________°F

J. Subcooling: ____________ °F ____________°F

K. Is the liquid in the sightglass clear and dry? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

L. Record discharge air temperature at discharge of unit: ___________ °F

M. Are all control lines secure to prevent excessive vibration and wear? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

N. Are all gauges shut off and valve caps and packings tight after start-up? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

VII. FURNACE CHECK, TEST, & START

A. Gas pressure at main:__________________ inches wc

B. Gas pressure at manifold:_______________ inches wc

C. High limit control OK? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

D. Flame failure shutoff: _______________ seconds

E. Airswitch OK? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

F. Main Gas Valve Close-Off OK? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

VIII. MAINTAINING MICROTECH CONTROL PARAMETER RECORDS

After the unit is checked, tested, and started and the final control parameters are set, record the final settings. Keep these records on file and update whenever changes to the control parameters are made. Keeping a record facilitates any required analysis and troubleshooting of the system operation and facilitates restoration after a controller replacement.

Circuit 1 ___________ psig Circuit 2___________ psig

Signature: ______________________________________________________ Startup date:____________________________________

RETURN COMPLETED FORM TO:

McQuay International Warranty Department, 13600 Industrial Park Boulevard, Minneapolis, MN 55441 Please list any additional comments that could affect the operation of this unit; e.g., shipping damage, failed components, adverse installation

applications, etc., on a separate sheet and attach to this form.

Registration Form

62 McQuay IM 1058

Quality Assurance Survey Report

To whom it may concern:

Please review the items below upon receiving and installing our product. Mark N/A on any item that does not apply to the product.

Job Name: _____________________________________________________ McQuay G.O. no. __________________

Installation Address: _____________________________________________________

City: __________________________________________________________ State: __________________

Purchasing Contractor: __________________________________________________

City:__________________________________________________________ State: __________________

Name of person doing start-up (print): _____________________________________________________

1. Is there any shipping damage visible? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Location on unit _____________________________________________________

2. How would you rate the overall appearance of the product; i.e., paint, fin damage, etc.?

Excellent Good Fair Poor

3. Did all sections of the unit fit together properly? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

4. Did the cabinet have any air leakage? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

Location on unit ___________________________________________________________________________

5. Were there any refrigerant leaks? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Shipping Workmanship Design

6. Does the refrigerant piping have excessive vibration?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Location on unit ___________________________________________________________________________

7. Did all of the electrical controls function at start-up? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Comments _______________________________________________________________________________

8. Did the labeling and schematics provide adequate information? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yes No N/A

9. How would you rate the serviceability of the product?

Excellent Good Fair Poor

10. How would you rate the overall quality of the product?

Excellent Good Fair Poor

11. How does the quality of McQuay products rank in relation to competitive products?

Excellent Good Fair Poor

Comments:

Please list any additional comments which could affect the operation of this unit; i.e., shipping damage, failed components, adverse installation applications, etc. If additional comment space is needed, write the comment(s) on a separate sheet, attach the sheet to this completed Quality Assurance Survey Report, and return it to the Warranty Department with the completed preceding “Equipment Warranty Registration Form”.

Yes No N/A

McQuay IM 1058 63

McQuay Training and Development

Now that you have made an investment in modern, efficient McQuay equipment, its care should be a high priority. For training information on all McQuay HVAC products, please visit us at www.mcquay.com and click on training, or call 540-248-9646 and ask for the Training Department.

Warranty

All McQuay equipment is sold pursuant to its standard terms and conditions of sale, including Limited Product Warranty. Consult your local McQuay Representative for warranty details. Refer to Form 933-43285Y. To find your local McQuay Representative, go to www.mcquay.com.

This document contains the most current product information as of this printing. For the most up-to-date product information, please go to www.mcquay.com.

McQuay MPS015F Installation Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Introduction

General Information

Unit Nameplate

Hazard Identification Information

Nomenclature (MPS 015–050)

Mechanical Installation

Installer Responsibilities

Receiving Inspection

Service Clearance

Ventilation Clearance

Overhead Clearance

Roof Curb Assembly and Installation

Rigging and Handling

Additional Weights for Motors/Exhaust Fans

Unit Piping - Condensate Drain Connection

Additional Weights for 6-Row DX Coil and HGRH Coil

Damper Assemblies

Cabinet Weather Protection

Installing Ductwork

Installing Duct Static Pressure Sensor Taps

Installing Building Static Pressure Sensor Taps

Electrical Installation

Field Power Wiring

Field Control Wiring

Preparing Unit for Operation

Spring Isolated Fans

Optional Gas Heat

Gas Furnace Design

Gas Heating Capacity Data

Installation

Gas Piping Routing Into Unit

Sequence of Operation (Staged Control)

Sequence of Operation (Modulating Burner)

Start-Up Procedures

Operating Procedures

Service

Maintenance

Ignition Control Module for Gas Furnace

Ignition Control Module for Modulating Gas Furnace

Variable Furnace Controller

Optional Electric Heat

Electric Heater Design

Electric Heating Capacity Data

Electric Heater Data

Optional Modulating Hot Gas Reheat

Modulating Hot Gas Reheat

Optional Hot Water Heat

Hot Water Heater Design

Hot Water Pressure Drop Data

Unit Options

Economizer Enthalpy Control

External Time Clock

Exhaust Fan Option

Proof-of-Airflow and Dirty Filter Switch

Duct High Pressure Limit

Convenience Receptacle (Field Powered)

Convenience Receptacle (Unit Powered)

Wiring Diagrams

Sequence of Operation

Fan Only

Minimum DAT

Start Up

Recirculation

Operating States

Heating

Mechanical Cooling

Economizer

Check, Test, and Start Procedures

Pre-Start of Unit

Servicing Control Panel Components

Before Start-Up

Power-Up

Fan Start-Up

Economizer Start-Up

Compressor Start-Up

Sheave Alignment