McQuay ACD 210 Installation Manual

Installation, Operation and Maintenance Manual

IOM ACAQ-1

Air-Cooled Condensers

Type ACS 010 Through ACS 100
Type ACD 045 Through ACD 210

Type AQS 020 Through AQS 085
Type AQD 040 Through AQD 170

Group: Chiller
Part Number: 331375101
Effective: January 2005

Supersedes: IOM ACAQ

Table of Contents

Product Offering ...............................................................................................................3

Introduction.......................................................................................................................4

Installation.........................................................................................................................4

Inspection.................................................................................................................................................. 4

Handling....................................................................................................................................................4

Holding Charge.........................................................................................................................................5

Unit Location.............................................................................................................................................5

Sound Vibration.........................................................................................................................................5

Walls or Obstructions................................................................................................................................ 6

Multiple Units ........................................................................................................................................... 7

Units in Pits............................................................................................................................................... 7

Decorative Fences.....................................................................................................................................7

Refrigerant Piping............................................................................................................. 8

Refrigerant Piping.....................................................................................................................................9

Discharge Lines......................................................................................................................................... 9

Physical Data ...................................................................................................................10

Electrical Data.................................................................................................................11

Operation .........................................................................................................................21

Start-Up................................................................................................................................................... 21

Discharge Gas Pulsation..........................................................................................................................21

Discharge Pressure Control.....................................................................................................................21

Maintenance..................................................................................................................... 26

Cleaning Instructions............................................................................................................................... 26

Manufactured in an ISO certified facility

2004 McQuay International

Illustrations cover the general appearance of McQuay International products at the time of publication and we reserve the right

to make changes in design and construction at anytime without notice.

2 Air-cooled Condensers IOM ACAQ -1

Product Offering

Model

ACS - 1140 rpm fan motors, single row of fans
ACD - 1140 rpm fan motors, double row of fans
AQS - 830 rpm fan motors, single row of fans
AQD - 830 rpm fan motors, double row of fans

Size

ACS 010 through ACS 100
ACD 045 through ACD 210
AQS 020 through AQS 085
AQD 040 through AQD 170

Voltage Option

42 = 208/230/ 60/ 3
27 = 460/ 60/ 3
37 = 575/ 60/ 3
Special – 208/ 60/ 1, 208/230/380/460/50/3

Control Option

A = Fan pressure control with control transformer (120V)
B = SpeedTrol and pressure control with control transformer (120V)
C = SpeedTrol
Y = None

Rough Duty Option

A = Totally enclosed motors
B = SealTite Wiring, special water tight conduit system
C = PolyGuard fin coating with totally enclosed motors and SealTite wiring
D = ElectroFin coating with totally enclosed motors and SealTite wiring

IOM ACAQ -1 Air-cooled Condensers 3

Introduction

Carefully check each shipment against the bill of lading and account for all items. Report
any shortage or damage to the delivering carrier.

Be careful to prevent damage when uncrating. Heavy equipment should be left on unit’s
shipping base until it has been moved to the final location.

This equipment must be installed in accordance with accepted industry standards. Failure
to meet the following conditions may void the warranty:

1. System piping must be installed following industry standards for good piping practices.

2. Inert gas must be charged into piping during welding.

3. System must be thoroughly leak checked and evacuated before initial charging. High

4. Power supply to system must meet the following conditions:

5. All controls and safety switch circuits properly connected per wiring diagram.

6. Factory installed wiring must not be changed without written factory approval.

7. Relief valves must meet all code requirements.

vacuum gauge capable of reading microns is mandatory. Dial indicating pressure
gauges are not acceptable.

S Voltage for 208/230 motors not less than 195 volts or more than 253 volts.
S All other voltages must be within 10% of nameplate ratings.
S Phase imbalance not to exceed 2%.

Installation

Inspection

When the equipment is received, carefully check all items against the bill of lading to check
for a complete shipment. Check all units for damage upon arrival. All shipping damage
must be reported to the carrier and a claim must be filed with the carrier. Check the unit’s
serial plate before unloading the unit to be sure that it agrees with the power supply
available. Physical damage to unit after acceptance is not the responsibility of McQuay
International.

Handling

Note: Installation and maintenance are to be performed only by qualified personnel who are
familiar with local codes and regulations, and experienced with this type of equipment.

Avoid rough handling shock due to impact or dropping the unit. Do not push or pull the
unit.

Never allow any part of the unit to fall during unloading or moving, as this can result in
serious damage.

DANGER

Improper lifting or moving unit can result in property damage, severe

personal injury or death. Follow rigging and moving instructions carefully.

4 Air-cooled Condensers IOM ACAQ -1

Holding Charge

The unit is shipped with a holding charge of dry nitrogen under nominal pressure.

Unit Location

Units are designed for outdoor application and may be mounted on a roof or concrete slab
(ground level installation). Install roof mounted units on steel channels or an I-beam frame
to support the unit above the roof. Use of vibration pads or isolators is recommended. The
roof must be strong enough to support the operating weight of the unit. For ground level
installation, mount units on a one-piece concrete slab with footings extending below the
frost line. Be certain concrete slabs are installed level and are properly supported to
prevent settling. Locate the condenser far enough away from any wall or other obstruction
to provide sufficient clearance for air entrance. Do not attach ductwork to the coil inlet or
fan outlet. Avoid air recirculation conditions that may be caused by sight screening, walls,
etc. and keep unit fan discharge away from any building air intakes. Do not install unit
where exhaust or ventilation equipment will affect entering air temperature or foul coils.

Sound Vibration

Install units away from occupied spaces, utility areas, corridors and auxiliary spaces to
reduce the transmission of sound and vibration to occupied spaces. The refrigerant piping
should be flexible enough to prevent the transmission of noise and vibration from the unit
into the building. If the refrigerant lines are to be suspended from the structure of the
building, use isolation hangers to prevent the transmission of vibration. Where piping
passes through a wall, pack fiberglass and sealing compound around the lines to minimize
vibration and retain flexibility. The unit must be secured in its final location. Holes are
provided in the base runner for this purpose.

IOM ACAQ -1 Air-cooled Condensers 5

Figure 1, Unit Rigging

Walls or Obstructions

Locate the unit to ensure air can
circulate freely and not be recirculated.
For proper air flow and access all sides
of the unit must be separated from the
wall as shown to the right. Increase
this distance whenever possible. Be
sure enough room is left for
maintenance through access doors and panels. Overhead obstructions are not permitted.
When enclosed by three walls the unit must be installed as indicated for units in a pit.

6 Air-cooled Condensers IOM ACAQ -1

AIR FLOW

ACS/ACD = 4 ft.
AQS/AQD = 6 ft.

Multiple Units

A

For units placed side by side, the
minimum distance between units
must be as shown to the right. If
units are placed end to end, the
minimum distance between units is
4 feet.

Units in Pits

The top of the unit should not be
more than two feet below top of the
pit, and side distance should be as
shown. If the top of the unit is not
level with the top of pit, discharge
cones or stacks must be used to raise
discharge air to the top of the pit.
This is a minimum requirement.

AIR FLOW

STACK

(BY OTHERS

IF SUPPLIED)

ACS/ACD = 4 ft.
AQS/AQD = 6 ft.

ACS/ACD = 6 ft.
AQS/AQD = 8 ft.

AIR

FLOW

AIR FLOW

2 FT. MAX.

ACS/ACD = 4 ft.
AQS/AQD = 6 ft.

Decorative Fences

Fences must have 50% free area,
with 1 foot undercut, at least the
width of condenser minimum
clearance, and must not exceed the
top of unit. If these requirements are
not met, unit must be installed as
indicated for "Units in pits".

1 IN.
MIN.

ACS/ACD

= 3 ft.

AQS/AQD

= 4 ft.

AIR FLOW

CS/ACD

= 3 ft.

AQS/AQD

= 4 ft.

IOM ACAQ -1 Air-cooled Condensers 7

Refrigerant Piping

Figure 2 illustrates a typical piping arrangement involving a remote condenser located at a
higher elevation, as commonly encountered when the condenser is on a roof and the
compressor and receiver are on grade level or in a basement equipment room. In this case,
the design of the discharge line is very critical. If properly sized for full load condition, the
gas velocity might be too low at reduced loads to carry oil up through the discharge line and
condenser coil. Reducing the discharge line size would increase the gas velocity
sufficiently at reduced load conditions; however, when operating at full load, the line would
be greatly undersized, and thereby create an excessive refrigerant pressure drop. This
condition can be overcome in one of two following ways:

1. Size discharge line for the desired pressure drop at full load conditions and install an oil
separator at the bottom of the trap in the discharge line from the compressor.

2. Use a double riser discharge line as shown in Figure 3. Size line "A" to carry the oil at
minimum load conditions and size line "B" at full load conditions; both lines would
have sufficient flow velocity to carry the oil to the condenser.

For more complete information, see the ASHRAE Handbook on Systems.
Be aware of the following when fabricating piping:

• All oil traps are to be as short in radius as possible. The trap may be fabricated using

three 90 degree ells.

• Use pressure relief valves at the condenser to protect the coil.

• Use a drain line check valve when the condenser is at a lower temperature than the

receiver.

Figure 2, Typical Piping Arrangement

Figure 3, Double Riser Discharge Piping

8 Air-cooled Condensers IOM ACAQ -1

Refrigerant Piping

Install piping according to standard accepted refrigeration practice. See Table 1 and Table 2
for discharge and liquid drain line sizes for remote condenser connections. Use only
refrigeration grade copper tubing and put dry nitrogen through lines while brazing.

CAUTION

Do not use soft solder joints. Do not leave dehydrated piping or com ponents open

to the atmosphere any longer than is absolutely necessary.

Valves

Major components should be equipped with isolation valves and a relief valve should be
installed in the discharge line between the check valve and the condenser inlet isolation
valve.

Discharge Lines

Design discharge lines so that refrigerant pressure drop is minimized (high pressure losses
cause increased compressor horsepower per ton of refrigerant) and a sufficiently high gas
velocity to carry oil through to the condenser coil and receiver at all loading conditions is
maintained.

Table 1, Discharge Line Sizing

Line Size

Type L

Copper

OD
1/2

5/8

7/8
1 1/8
1 3/8
1 5/8
2 1/8
2 5/8
3 1/8
3 5/8
4 1/8

Notes:

1. Source: ASHRAE Refrigeration Handbook:

2. Line sizes based on pressure drop equivalent to 1'F per 100 equivalent f eet

3. Values in Table are based on 1051F condensing temperature. Multiply Table capacities by the factors in
Table 2 for other condensing temperat ures.

4. If subcooling is substantial or the li ne i s short, a smaller li ne size may be used. Applications with very littl e
subcooling or very long lines may require larger sizes.

Sat. Suction Temp. (°F) Sat. Suction Temp. (°F)

-40 0 40 -40 0 40 R-22 R-502

0.75 0.8 0.85 0.56 0.63 0.7 2.3 1.5

1.4 1.5 1.6 1.0 1.2 1.3 3.7 2.3

3.7 4.0 4.2 2.7 3.1 3.4 7.8 4.9

7.5 8.0 8.5 5.5 6.3 7.0 13.2 8.3

13.1 14.0 14.8 9.6 10.9 12.1 20.2 12.6

20.7 22.0 23.4 15.2 17.2 19.1 28.5 17.9

42.8 45.7 48.5 31.4 35.6 39.5 49.6 31.1

75.4 80.4 85.4 55.3 62.8 69.5 76.5 48.0

120.2 128.2 136.2 87.9 99.8 110.5 109.2 68.4

178.4 190.3 202.1 130.5 148.1 164.0 147.8 92.6

251.1 267.8 284.4 183.7 208.4 230.9 192.1 120.3

R-22 R-404A, R-507

Discharge Line

Drain Line

Velocity 100 FPM

Refrigerant

Table 2, Condensing Temperature Correction Factor

Condensing

Temperature

90
100
110
120
130

IOM ACAQ -1 Air-cooled Condensers 9

Discharge Line

R-22 R-404, R-507

0.88 0.91

0.95 -0.97

1.04 1.02

1.10 1.08

1.18 1.16