McQuay ACH 014 Installation Manual
Installation, Operation and Maintenance Manual
IOMM A-C Cond
Air-Cooled Condensers
Model ACH 014 - 225
Model ACX 014 - 225
Model ACL 014 - 225
Capacities from 130 MBH to 2225 MBH
R-22, R-134a
Group: Chiller
Part Number: 331376901
Effective: AUGUST 2007
Supersedes:
JULY 2007
Table of Contents
Introduction................................................................................... 3
Installation..................................................................................... 3
Handling .........................................................................................................3
Holding Charge...............................................................................................3
Unit Location..................................................................................................4
Sound/Vibration..............................................................................................4
Rigging ...........................................................................................................5
Walls or Obstructions......................................................................................5
Multiple Units.................................................................................................6
Units in Pits.....................................................................................................6
Decorative Fences...........................................................................................6
Dimensions..................................................................................... 7
Refrigerant Piping......................................................................... 8
Refrigerant Piping...........................................................................................8
Valves..............................................................................................................8
Discharge Lines ..............................................................................................9
R-410A ...........................................................................................................9
Physical Data...............................................................................10
Electrical Data..............................................................................11
Operation..................................................................................... 18
Start-Up.........................................................................................................18
Discharge Gas Pulsation...............................................................................18
Discharge Pressure Control ..........................................................................18
Fan/Circuit Configuration .............................................................................18
Control options:............................................................................................19
Maintenance ................................................................................ 26
Cleaning Instructions....................................................................................26
Manufactured in an ISO certified facility
©2007 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 IOMM A-C Cond
MODEL CODE
AC H 100 A S
Air-cooled Condenser
Series: H, L, X
Nominal Evaporator Tons
Fan Rows/Circuits
S=Single, D=Dual
Vintage
Introduction
Carefully check each shipment against the bill of lading and account for all items. Report any shortage or
damage to the delivering carrier.
On receipt of equipment, check the unit nameplate for correct electrical characteristics and working pressure.
Refrigerants R-22, R-134a, R-407c have 450 psi; R-410a has 650 psi.
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 brazing/welding.
3. System must be thoroughly leak-checked and evacuated before initial charging. High vacuum gauge capable
of reading microns is mandatory. Dial indicating pressure gauges are not acceptable.
4. Power supply to system must meet the following conditions:
Voltage for 208/230 motors not less than 195 volts or more than 253 volts.
All other voltages must be within 10% of nameplate ratings.
Phase imbalance not to exceed 2%.
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.
Installation
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 of unit can result in property damage, severe personal injury
or death. Follow rigging and moving instructions carefully.
Holding Charge
The unit is shipped with a holding charge of dry nitrogen under nominal pressure.
IOMM A-C Cond 3
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.
! WARNING
Warnings indicate potentially hazardous situations, which can result
in property damage, severe personal injury, or death if not avoided.
This equipment may contain a substance which harms the public
health and environment by destroying ozone in the upper
atmosphere. Venting of certain refrigerants to the atmosphere is
illegal. Refrigerant recovery devices must be used when installing or
servicing this product.
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.
4 IOMM A-C Cond
Rigging
A
A
A
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, maintain the
minimum distance from the unit to the wall as shown to the right.
Increase this distance whenever possible. Leave maintenance
room through access doors and panels. Overhead obstructions are
not permitted. When enclosed by three walls, install unit as
indicated for units in a pit.
IOMM A-C Cond 5
IR FLOW
CH = 4 ft.
CL/ACX = 6 ft.
Multiple Units
A
A
A
A
A
A
A
A
A
A
A
A
A
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.
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".
IR FLOW
1 IN.
MIN.
STACK
(BY OTHERS
IF SUPPLIED)
CH = 4 ft.
CL/ACX = 6 ft.
CH = 6 ft.
CL/ACX = 8 ft.
IR
FLOW
CH = 3 ft
.
CL/ACX
= 4 ft.
2 FT. MAX.
IR FLOW
IR FLOW
CH = 4 ft.
CL/ACX = 6 ft.
CH = 3 ft
CL/ACX
= 4 ft.
6 IOMM A-C Cond
Dimensions
Note: All dimensions in inches
unless otherwise indicated
IOMM A-C Cond 7
Refrigerant Piping
R
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 the 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 2
conditions and size line "B" at full load conditions; both lines should 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 and Double Riser Discharge Piping Arrangement
. Size line "A" to carry the oil at minimum load
CONDENSER
Check Valve
h
c
t
i
P
Discharge
Line
Relief
Valve
RECEIVE
Typical Piping Arrangement
Liquid
Line
Trap
h
c
t
i
P
COMPRESSOR
Double Riser Discharge Piping Arrangement
Refrigerant Piping
Install piping according to standard accepted refrigeration practice. See Ta b le 1 and Ta bl e 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
Cautions indicate potentially hazardous situations which can result in
personal injury or equipment damage if not avoided.
Do not use soft solder joints. Do not leave dehydrated piping or
components open to the atmosphere any longer than is absolutely
necessary.
Valves
Equip major components with isolation valves and install a relief valve in the discharge line between the check
valve and the condenser inlet isolation valve.
8 IOMM A-C Cond
Discharge Lines
Design discharge lines so that refrigerant pressure drop is minimized (high pressure losses cause increased
compressor horsepower) 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 (in.)
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 one degree F. per 100 equivalent feet
3. Values in Table are based on 105°F condensing temperature. Multiply Table capacities by the factors in
4. If the line is short, a smaller line size may be used and very long lines may require larger sizes.
128.2 132.2 136.2 86.7 91.2 95.5 130.5 136.0 141.2 198.4 204.3 209.0
190.3 196.2 202.1 129.0 135.0 142.0 193.3 201.4 209.2 293.9 302.7 309.6
267.8 276.1 284.4 181.0 191.0 200.0 272.6 284.0 295.0 413.8 426.1 435.9
temperatures.
R-22 R-134a R-407C R-410A
Sat. Suction Temp. Sat. Suction Temp. Sat. Suction Temp Sat. Suction Temp
0°F 20°F 40°F 0°F 20°F 40°F0°F 20°F 40°F0°F 20°F 40°F
0.8 0.8 0.8 0.5 0.6 0.6 0.8 0.9 0.9 1.3 1.3 1.3
1.5 1.6 1.6 1.0 1.1 1.1 1.5 1.6 1.7 2.4 2.4 2.5
4.0 4.1 4.2 2.7 2.8 2.9 4.1 4.2 4.4 6.2 6.4 6.5
8.0 8.3 8.5 5.4 5.7 6.0 8.2 8.5 8.9 12.5 12.9 13.2
14.0 14.4 14.8 9.4 9.9 10.4 14.2 114.8 15.4 21.7 22.4 22.9
22.1 22.7 23.4 14.9 16.7 16.4 22.5 23.4 24.3 34.3 35.3 36.1
45.7 47.1 48.5 30.8 32.4 34.0 46.5 48.4 50.3 70.8 72.8 74.6
80.4 82.9 85.4 54.4 57.2 59.9 82.0 85.4 88.7 124.5 128.3 131.2
Discharge Line Capacity in Evaporator Tons
Table 2 for other condensing
Table 2, Condensing Temperature Correction Factor
Condensing
Temperature
90°F
100°F
110°F
120°F
130°F
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
Table 3, Liquid Line Sizing
Line Size
Type L
Copper
OD (in.)
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
In Evaporator Tons at 100 FPM Velocity
R-22 R-134a R-407C R-410A
13.2 12.1 37.9 45.8
20.2 18.4 66.2 79.7
28.5 26.1 104.7 125.9
49.6 45.3 317.1 260.7
76.5 69.9 383.7 459.7
109.2 100.0 611.3 733.0
147.8 135.0 907.9 1087.5
192.1 175.0 1281.5 1530.2
Liquid Line Capacity
2.3 2.1 3.8 4.6
3.7 3.4 7.1 8.6
7.8 7.1 18.7 22.6
R-410A
R-410A can have discharge pressures well in excess of 450 psi and special care must be exercised in designing
and installing refrigerant components and piping.
IOMM A-C Cond 9
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