McQuay ALR 028E Installation Manual
Installation, Operation and Maintenance Manual IOMM ALR2
Packaged Air-Cooled Water Chiller
Models ALR 020E Through ALR 030E
60 Hertz
Group: Chiller
Part Number: 629951
Effective: June 1999
Supersedes: IM 688
© 1997 McQuay International
Table of Contents
Introduction.........................................3
General Description................................................3
Inspection................................................................3
Installation...............................................................3
Handling..................................................................3
Location...................................................................4
Service Access........................................................5
Vibration Isolators..................................................6
Water Piping............................................................6
Flow Switch.............................................................8
Water Connections................................................9
Refrigerant Charge.................................................9
Glycol Solutions.....................................................9
Evaporator Water Flow and Pressure Drop........9
Unit Layout and Operation...............11
Control Center .......................................................11
Start-up and Shutdown......................11
Pre Start-up............................................................11
Start-up..................................................................11
Sequence of Operation........................................12
Electrical Data..................................14
Field Wiring...........................................................14
Dimensional Data.............................18
System Maintenance........................18
General...................................................................18
Fan Motor Bearings.............................................18
Electrical Terminals...............................................18
Condensers ...........................................................18
Refrigerant Sightglass.........................................19
Service...............................................19
Thermostatic Expansion Valve...........................19
Filter-Driers............................................................19
Liquid Line Solenoid............................................20
Standard Controls ................................................20
Compressor Lockout............................................22
Optional Controls .................................................23
Control Settings....................................................26
Troubleshooting Chart........................................27
Physical Data....................................13
"McQuay" is a registered trademark of 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"
1997 McQuay International
2 ALR 020E through 030E IOMM ALR2
Introduction
General Description
McQuay air-cooled water chillers are complete, self-contained automatic refrigerating units. Every
unit is completely assembled, factory wired, charged, and tested. Each unit consists of two air-cooled
condensers connected in parallel with integral subcooler sections, Copeland DISCUS semi-hermetic
compressor, single circuit brazed plate-to-plate evaporator, and complete refrigerant piping. Liquid
line components include manual liquid line shutoff valve, sight-glass/moisture indicator, solenoid
valve, and double diaphragm hydraulic element thermal expansion valve. Other features include a
compressor crankcase heater, an evaporator heater for chilled water freeze protection, and a hot gas
muffler.
The electrical control center includes all safety and operating controls necessary for dependable
automatic operation. Condenser fan motors are three phase (except single phase on No. 1 fan with
FanTrol option) and started by their own contactors and have inherent overload protection. The
compressor is not fused but has solid state motor protection for inherent thermal overload protection.
Inspection
Check all items carefully against the bill of lading. Inspect all units for damage upon arrival. Report
shipping damage and file a claim with the carrier. Check the unit name plate before unloading, making
certain it agrees with the power supply available. Units are shipped fob factory and McQuay is not
responsible for physical damage after unit leaves the factory.
Note: Unit shipping and operating weights are listed on page 13, Table 3.
Installation
Note: Installation is to be performed by qualified personnel who are familiar with local codes
and regulations especially concerning refrigerant release to the atmosphere.
WARNING
Sharp edges and coil surfaces are a potential hazard. Avoid contact with them.
Handling
Be careful to avoid rough handling of the unit. Do not push or pull the unit from anything other than
the base. Block the pushing vehicle away from the unit to prevent damage to the sheet metal cabinet
and end frame (see Figure 1).
To lift the unit, lifting slots are provided in the base of the unit. Arrange spreader bars and cables to
prevent damage to the condenser coils or cabinet (see Figure 2).
IOMM ALR2 ALR 020E through 030E 3
Figure 1, Suggested pushing arrangement
Figure 2, Suggested lifting arrangement
Blocking required
across full width
Location
Unit Placement
ALR units are for outdoor applications and can be mounted on a roof or ground level. Set units on a
solid and level foundation. For roof mounted applications, install the unit on a steel channel or I-beam
frame to support the unit above the roof. For ground level applications, install the unit on a
substantial base that will not settle. A one-piece concrete slab with footings extended below the frost
line is recommended. Be sure the foundation is level (within 1/2” [13 mm] over its length and width).
The foundation must support the operating weights listed in the Physical Data Table on page 13.
Unit operation is affected by wind and it should located so that length is parallel with the prevailing
wind. If this is not practical, field fabricated wind deflectors should be employed.
Clearances
The flow of air to and from the condenser coil must not be limited. Restricting airflow or allowing air
recirculation will result in a decrease in unit performance and efficiency. There must be no obstruction
above the unit that would deflect discharge air downward where it could be recirculated back to the
inlet of the condenser coil. The condenser fans are propeller type and will not operate with ductwork
on the fan outlet.
4 ALR 020E through 030E IOMM ALR2
Install the unit with enough side
clearance for air entrance to the coil and
for servicing. Provide service access to
the evaporator, compressors, electrical
control panel and piping components
as shown in Figure 3. Do not block
access to the unit with piping or
conduit.
Do not allow debris to accumulate near
the unit. Air movement may draw
debris into the condenser coil causing
air starvation. Give special
consideration to low ambient operation
where snow can accumulate. Keep
condenser coils and fan discharge free
of snow or other obstructions to permit
adequate airflow.
Sound Isolation
The low sound levels of the ALR chiller
are suitable for most applications.
When additional sound reduction is
necessary, locate the unit away from
sound sensitive areas. Avoid locations
beneath windows or between
structures where normal operating
sounds may be objectionable. Reduce
structurally transmitted sound by
isolating water lines, electrical conduit
and the unit itself. Use wall sleeves
and rubber isolated piping hangers to
reduce transmission of water or pump
noise into occupied spaces. Use
flexible electrical conduit to isolate
sound through electrical conduit.
Spring isolators are effective in
reducing the low amplitude sound
generated by the Discus semi-hermetic
compressors and for unit isolation in
sound sensitive areas.
Figure 3, Clearance requirements
Service Access
Each end of the unit must be accessible
after installation for periodic service.
Compressors, filter-driers, and manual
liquid line shutoff valves are accessible
from the end of the unit. High pressure,
low pressure, and motor protector controls are on the compressor. Most operational, safety and
starting controls are located in the unit control box.
The condenser fan and motors can be removed from the top of the unit.
IOMM ALR2 ALR 020E through 030E 5
Vibration Isolators
Vibration isolators are recommended for all roof mounted installations or wherever vibration
transmission is a consideration. The isolators can be purchased from McQuay by the part numbers
shown in the table. Install spring isolators under the main unit support according to the dimension
drawing. Adjust springs to allow the upper housing to clear the lower housing by 1/4” to 1/2”. An
anti-skid pad should be used if hold-down bolts are not used.
Table 1, Recommended Vibration Isolators
ALR UNIT ISOLATOR
TYPE
020E-028E Rubber-in-shear 00-216397-01 4 RP-3 Red 525
030E Rubber-in-shear 00-216397-01 2 RP-3 Red 525
020E-028E Spring Isolators 00-477927-26 4 CP-1-26 600
030E Spring Isolators 00-477927-26 2 CP-1-26 600
Note: See dimension drawing for location of isolators
McQUAY
PART NO.
00-216397-03 2 RP-3 Green 725
00-447927-27 2 CP-1-27 750
NUMBER
REQUIRED
ISOLATOR
DESCRIPTION
MAX. LOAD
EACH (LBS)
Water Piping
Local authorities can supply the installer with the proper building and safety codes required for safe
and proper installation.
Install piping with minimum bends and changes in elevation to minimize pressure drop. Consider the
following when installing water piping:
1. Vibration eliminators to reduce vibration and noise transmission to the building.
2. Shutoff valves to isolate the unit from the piping system during unit servicing.
3. Manual or automatic air vent valves at the high points of the system. Install drains at the lowest
points in the system.
4. A means of maintaining adequate system water pressure (expansion tank or regulating valve).
5. Temperature and pressure indicators located at the unit to aid in unit servicing. Pressure gauge
taps must be installed in the chilled water inlet and outlet piping or as shown in Figure 4.
6. A strainer or other means of removing foreign matter from the water before it enters the pump.
Place the strainer far enough upstream to prevent cavitation at the pump inlet (consult pump
manufacturer for recommendations). The use of a strainer will prolong pump life and keep system
performance up.
7. Place a strainer in the water line just before the inlet of the evaporator. This will help prevent
foreign material from entering and decreasing the performance of the evaporator.
CAUTION
If separate disconnect is used for the 110V supply to the evaporator heating cable, mark the
disconnect clearly to ensure disconnect is not accidentally shut off during cold seasons.
8. The brazed plate evaporator has a thermostat and heating cable to prevent freeze-up down to 20°F (-29°C). It is suggested that the heating cable be wired to a separate 110V supply circuit. As
shipped from the factory, the heating cable is wired to the control circuit. All water piping to the
unit must also be protected to prevent freezing.
9. If the unit is used as a replacement chiller on a previously existing piping system, flush the
system thoroughly before unit installation. Regular water analysis and chemical water treatment
on the evaporator is recommended immediately at equipment start-up.
6 ALR 020E through 030E IOMM ALR2
10. The total water volume in the system should be sufficient to prevent frequent “on-off” cycling.
Turnover rate should not be less than 15 minutes for normal variable cooling loads. Turnover
rate for a constant load should not be less than 6 minutes.
IOMM ALR2 ALR 020E through 030E 7
11. When glycol is added to the water system for freeze protection, the refrigerant suction pressure
will be lower, cooling performance less, and water side pressure drop greater. If the percentage of
glycol is high, or if propylene is used instead of ethylene glycol, the added pressure drop and
loss of performance could be substantial. Reset the freezestat and low leaving water alarm
temperatures. The freezestat is factory set to default at 36°F (2.2°C). Reset the freezestat setting
to approximately 4 to 5 degrees F (2.3 to 2.8 degrees C) below the leaving chilled water setpoint
temperature. See the section titled “Glycol Solutions” for additional information concerning
glycol.
12. Perform a preliminary leak check before insulating the piping and filling the system.
13. Piping insulation should include a vapor barrier to prevent condensation and possible damage to
the building structure.
Figure 4, Typical Field Evaporator Water Piping
Note: the above piping is correct for both brazed plate and tube-in-shell evaporators
Flow Switch
Mount a water flow switch in the leaving water line to shut down the unit when water flow is
interrupted.
A flow switch is available from McQuay (part number 0701804-04). It is a “paddle” type switch and
adaptable to pipe sizes down to 1 1/4 ” (32mm) nominal. Certain minimum flow rates are required to
close the switch and are listed in Table 2. Installation should be as shown in Figure 5. Connect the
normally open contacts of the flow switch in the unit control center at terminals 4 and 5. There is also
a set of normally closed contacts on the switch that can be used for an indicator light or an alarm to
indicate when a “no flow” condition exists. Freeze protect any flow switch that is installed outdoors.
NOTE: Differential pressure switches are not recommended for outdoor installation.
Table 2, Flow Switch Settings
mm 32 38 51 63 76 102Pipe Size
inch 1 1/4 1 1/2 2 2 1/2 3 4
gpm 4.8 6.3 9.9 15.3 24.4 33.3Flow
Minimum
Adjustment
Maximum
Adjustment
No
Flow
No
Flow
Lpm 18.2 22.7 37.5 57.9 92.4 126.0
gpm 3.0 3.6 5.9 9.5 15.4 21.1
Lpm 11.3 13.6 22.3 36.0 58.3 79.9
gpm 7.7 10.0 15.8 23.7 35.5 61.4Flow
Lpm 29.1 37.9 59.8 89.7 134.4 232.4
gpm 5.9 7.0 11.0 17.0 29.2 37.7
Lpm 22.3 26.5 41.6 64.3 110.5 142.7
8 ALR 020E through 030E IOMM ALR2
Figure 5, Flow Switch Installation
Water Connections
Bring water piping to the cooler from the end of the unit, in the top and out the bottom connection.
Refrigerant Charge
All units are designed for use with HCFC-22 and other refrigerants. See nameplate for specific
refrigerant used. Units are shipped with an operating charge. The operating charge
(using HCFC-22) for each unit is shown in the Physical Data Table on page 12.
Glycol Solutions
The use of glycol anti-freeze solutions will decrease unit capacity, and increase the pressure drop
through the cooler. See Product Manual 985 for specific ratings and correction factors.
CAUTION
Do not use automotive grade antifreeze. Industrial grade glycols must be used. Automotive
antifreeze contains inhibitors that will cause plating on the copper tubes within the chiller
evaporator. The type and handling of glycol used must be consistent with local codes.
Evaporator Water Flow and Pressure Drop
Evaporator flow rate must fall between the minimum and maximum values shown in the evaporator
pressure drop curve, Figure 6. Flow rates below the minimum values will result in laminar flow that will
reduce efficiency, cause erratic operation of the expansion valve and could cause low temperature
cutouts. Flow rates exceeding the maximum values can cause erosion on the evaporator water
connections and tubes.
Measure the chilled water pressure drop through the evaporator at field installed pressure taps. It is
important not to include the effect of valves or strainers in these readings.
Varying chilled water flow through the evaporator while the compressor are operating is not
recommended.
IOMM ALR2 ALR 020E through 030E 9
Loading...