McQuay LDE Installation Manual
Installation & Maintenance Data IM 439-15
Large Vertical Water Source Heat Pumps
6 thru 25 Tons
Models LDD, LDE, LDL, LDS, LME, LMH, LML, LMS
Group: WSHP
Part Number: 106581103
Date: June 2006
©2006 McQuay International
®
Contents
Model Nomenclature .................................................... 2
Transportation and Storage ......................................... 2
Installation.................................................................. 3-6
Piping ............................................................................ 7
Cleaning and Flushing System ..................................... 8
Start-up ...................................................................... 8-9
Operating Limits ........................................................... 9
Electrical Data ............................................................... 9
Typical Wiring Diagrams ........................................ 10-13
Model Nomenclature
W LDD 1 070 D Z
Product Category
W = WSHP
Product Identifier
See box below
Typical Mark IV/AC units ................................. 10-11
Typical MicroTech units .................................. 12-13
Unit Operation ............................................................ 14
Mark IV Sequence of Operation ................................. 15
Thermostat Connections............................................ 16
Miscellaneous Options on Mark IV Units .............. 17-20
Field Installed Options on MicroTech Units ................ 21
Troubleshooting WSHP .............................................. 22
Maintenance ............................................................... 23
Design Series
1 = A Design
2 = B Deisgn
3 = C Design
4 = D Design
5 = E Design
Nominal Capacity
070 = 70,000
108 = 108,000
121 = 121,000
Coil Options
(None)
Voltage
D= 208-60-3
H= 230-60-3
K= 460-60-3
L= 575-60-3
N= 380-50-3
180 = 180,000
215 = 215,000
290 = 290,000
etc. . .
McQuay Product Identifiers
LDD = Std. Large Vertical/DDC Controls/Std. Range/Less Board LME = Std. Large Verical/Mark IV/Ext. Range
LDE = Std. Large Vertical/DDC Controls/Ext. Range LMH = High Static Large Vertical/Mark IV/Std. Range
LDL = Std. Large Vertical/DDC Controls/Ext. Range/Less Board LML = High Static Large Vertical/Mark IV/Ext. Range
LDS = Std. Large Vertical/DDC Controls/Std. Range LMS = Std. Large Vertical/Mark IV/Std. Range
Page 2 of 24 / IM 439
Note: Installation and maintenance are to be performed only
by qualified personnel who are familiar with local
codes and regulations, and are experienced with this
type of equipment.
CAUTION
!
Sharp edges are a potential injury hazard. Avoid contact with
them.
Transportation and Storage
Upon receipt of the equipment, check unit for visible damage. Make a notation on the shipper’s delivery ticket before
signing. If there is any evidence of rough handling, the
cartons should be opened at once to check for concealed
damage. If any damage is found, notify the carrier within 48
hours to establish your claim and request their inspection
and a report. The Warranty Claims Department should then
be contacted.
Do not stand or transport the machines on end. For storing,
each unit must be in the “up” position.
In the event that elevator transfer makes upended positioning unavoidable, absolutely ensure that the machine is in the
normal upright position for at least 24 hours before operating.
Temporary storage at the jobsite must be indoors, completely sheltered from rain, snow, etc. High or low temperatures naturally associated with weather patterns will not
harm the conditioners. Excessively high temperatures 140°F
(60°C) may deteriorate certain plastic materials and cause
permanent damage. In addition, the solid-state circuit boards
may experience operational problems.
Installation
General
1. To prevent damage, this equipment should not be oper-
ated for supplementary heating and cooling during the
construction period.
2. Inspect the shipping label for any specific tagging numbers
indicated per request from the installing contractor. At this
time the voltage, phase and capacity should be checked
against the plans.
3. Check the unit size against the plans to be sure that the unit
will be installed in the correct location.
4. After removing the packaging material, remove unit from
the skid.
5. Before installation, check the available dimensions versus
the dimensions of the unit.
6. Pay attention to the location and routing of water piping,
condensate drain piping, and electrical wiring. The loca-
tions of these items are clearly marked on submittal
drawings.
7. The installing contractor will find it beneficial to confer with
piping, sheetmetal, ceiling and electrical foremen together
before installing any conditioners.
Note: Check the unit name plate for correct voltage with the
plans before installing the equipment. Also, make sure
all electrical ground connections are made in accordance with local code.
8. We recommend that the contractor cover the conditioners
with plastic film to protect the machines during finishing of
the building. This is important if spraying fireproofing
material on bar joists, sandblasting, spray painting and
plastering operations have not been completed.
Unit Location
1. Locate the unit in an area that allows for easy removal of
the filter and access panels, and has enough space for
service personnel to perform maintenance or repair. Provide sufficient room to make water, electrical and duct connections
(see Figure 1 for service clearance details)
.
2. The contractor should make sure that access has been
provided including clearance for 2" (51 mm) thick filter brackets, duct collars and fittings at water and electrical connections.
3. Allow adequate room around the unit for a condensate trap.
4. The unit can be installed “free standing” in an equipment
room. Generally, the unit is located in a separate room with
the non-ducted return air facing the return air intake. Alternatively, the unit can have a ducted return air.
5. It is recommended that the unit be located on vibration isolators to reduce any vibration
(see Figure 3)
.
6. If optional field installed controls are required (Boilerless
System), space must be provided for the enclosure to mount
on the side of the unit.
Figure 1. Service clearance
Side B
Fan Motor
Side A
24" (610 mm)
Control Box
Location
24"
(610 mm)
Piping
Location
IMPORTANT
1. A 24" (610 mm) minimum clearance is required on the
return air, control box and piping sides. However, a 36"
(914 mm) clearance allows for easier serviceability.
2. A 12" (305 mm) minimum clearance is required on Side
A to gain access to panel to remove locking collar for shaft
removal.
3. A 6" (152 mm) clearance is required on Side B to remove
screws holding top panel.
4. Top clearance is required for fan shaft removal.
5. Some codes dictate a 60" (1524 mm) clearance above
the control box which could be violated with a ducted
return. Check your codes.
IM 439 / Page 3 of 24
Unit Arrangement
Two fan discharges and piping arrangements are available.
With the return air side defined as the “front” of the unit, the
water piping and electrical power connections may be righthand (side) or left-hand. The main control panel is located in
the center of the unit, lower section under the return air filter.
Unit sides opposite the control panel and opposite the piping
side may be up against walls and still allow for service and
maintenance through the remaining access panels.
Filter Access
Each unit is shipped with a filter bracket for side filter
removal.
Figure 2. Side view from piping end
M
M
Piping
Control Box Location
Piping
Fan Motor
Vibration Isolation
For minimum sound and vibration transmission, it is recommended that the unit be mounted on vibration isolators.
Holes are provided in the bottom panel to facilitate con-
nection of isolators
(see Figure 3 for hole locations)
Isolators supplied by the manufacturer are the type shown
in Figures 4 and 5. Four white isolators are used for single
compressor units and six green isolators are used for dual
compressor units. The holes in the bottom of the unit allow for
3
⁄8" (10 mm) bolt to be secured to the isolator.
a
Figure 4. Single compressor unit — vibration isolators
3" (76 mm)
7
(4)
5
/32"
28
(715 mm)
3" (76 mm)
3" (76 mm)
23
54
/32"
(1390 mm)
.
/16" (11 mm) holes
Figure 3. Isolator
25/8" (61 mm)
7
/16" (11 mm) dia.
AA
3" (76 mm)
1
/
4
2"
(51 mm)
Section A-A
3
" (114 mm)
2
1
" (140 mm)
2
/
5
7
/16" (11 mm)
/8" (10 mm) TAP
21/2" (64 mm)
1
/4" (6 mm)
Figure 5. Dual compressor unit — vibration isolators
2" (51 mm)
1
/8"
30
(765 mm)
2" (51 mm)
1
3
/4" (83 mm)
3
80
/8"
(2042 mm)
Page 4 of 24 / IM 439
(6) 3/8" (10 mm) holes
3
/16"
40
(1021 mm)
1
/4" (83 mm)
3
Air Balancing
All units are supplied with a variable pitch motor sheave to aid
in airflow adjustment. They are typically set at the low end of
the rpm range for field adjustment to the required airflow.
When the final adjustments are complete, the current
draw of the motors should be checked and compared to the
full load current rating of the motors. The amperage must not
exceed the service factor stamped on the motor nameplate.
Upon completion of the air balance, it is a common
industry recommendation that the variable pitched motor
sheave be replaced with a properly sized fixed sheave. A
matching fixed sheave will provide longer belt and bearing
life and vibration free operation. Initially, it is best to have a
variable pitched motor sheave for the purpose of air balancing,
but once the balance has been achieved, fixed sheaves
maintain balancing and alignment more effectively.
Adjustment (See Figure 6)
1. All sheaves should be mounted on the motor or driving
shaft with the setscrew “A” toward the motor.
2. Be sure both driving and driven sheaves are in alignment
and that shafts are parallel.
3. Fit internal key “D” between sheave and shaft, and lock
setscrew “A” securely in place.
4. Put on belts and adjust belt tension to 4 lbs. ± 0.7 lbs.
(18 ± 3N) for a
1
⁄2" to 3⁄4" (13 mm to 19 mm) belt deflection
height.
5. To determine the deflection distance from normal position,
use a straightedge or stretch a cord from sheave to sheave
to use as a reference line. On multiple-belt drives an adjacent
undeflected belt can be used as a reference.
6. Future adjustments should be made by loosening the belt
tension and increasing or decreasing the pitch diameter
of the sheave by half or full turns as required. Readjust belt
tension before starting drive.
7. Be sure that all keys are in place and that all setscrews are
tight before starting drive. Check setscrews and belt tensio n
after 24 hours service.
8. When new V-belts are installed on a drive, the initial
tension will drop rapidly during the first few hours. Check
tension frequently during the first 24 hours of operation.
Subsequent retensioning should fall between the minimum and maximum force.
Figure 7. Drive belt adjustment
Adjusting:
1. Loosen setscrews “B” and “C” in moving parts of sheave
and pull out external key “E”. (This key projects a small
amount to provide a grip for removing.)
2. Adjust sheave pitch diameter for desired speed by opening moving parts by half or full turns from closed position.
Do not open more than five full turns.
3. Replace external key “E” and securely tighten setscrews
“B” over key and setscrews “C” into keyway in fixed half of
the sheave.
Figure 6.
“A”
“B”
“E”
“D”
Span Length (t)
Deflection
Force
D
h
d
C
t
h=
64
t= C2 –
√
Where:
t= Span length, inches (mm)
C= Center distance, inches (mm)
D= Larger sheave diameter, inches (mm)
d= Smaller sheave diameter, inches (mm)
h= Deflection height, inches (mm)
Note: The ratio of deflection to belt span is 1:64.
D-d
()
2
Single Groove
“C”
Key “E” projects to
provide a grip for
removing.
IM 439 / Page 5 of 24
Ductwork and Attenuation
Discharge ductwork is normally used with these conditioners.
Return air ductwork may also be required but will require field
installation of a return air duct collar.
All ductwork should conform to industry standards of good
practice as described in ASHRAE Systems Guide.
The discharge duct system will normally consist of a flexible connector at the unit, a transition piece to the final duct
size, a short run of duct, an elbow without vanes and a trunk
duct tee’d into branch ducts with discharge diffusers as shown
in Figure 10. Transition piece must not have angles totalling
more than 30 degrees or severe loss of air performance can
result.
All units have multiple fan outlets. A single duct can enclose all the openings as shown in Figure 10; however, the
preferred method for minimum static pressure loss would be
individual ducts at each outlet connected to a larger duct downstream.
For minimum noise transmission, the metal duct material
should be internally lined with acoustic fibrous insulation.
The ductwork should be laid out so that there is no line of
sight between the conditioner discharge and the distribution
diffusers.
Return air ducts can be brought in adjacent to the return
air of the conditioner. T ypically, the equipment room becomes
the common return air plenum.
Do not insert sheetmetal screws directly into the unit cabinet for connection of supply or return air ductwork, especially
return air ductwork which can hit the drain pan or the air coil.
Ventilation Air
Outside air may be required for ventilation. The temperature
of the ventilation air must be controlled so that mixture of outside air and return air entering the conditioner does not exceed conditioner application limits. It is also general practice
to close off the ventilation air system during unoccupied periods (night setback).
The ventilation air system is generally a separate building subsystem with distribution ductwork. Simple introduction
of the outside air into each return air plenum chamber reasonably close to the conditioner air inlet is not only adequate,
but recommended. Do not duct outside air directly to the conditioner inlet. Provide sufficient distance for thorough mixing
of outside and return air
(see Operating Limits on page 9).
Optional Duct Collar and 2" (51 mm)
Filter Rack
The optional duct collar kit is used to facilitate connection of
return air duct to the unit. The duct collar kit can be used in
conjunction with the standard 1" (25 mm) thick filter rack or
the optional 2" (51 mm) filter rack.
The 2" (51 mm) filter rack facilitates the installation of 2"
(51 mm) thick filters for side removal. The 2" (51 mm) filter
rack replaces the existing 1" (25 mm) filter rack and does not
require the use of the optional return air duct collar.
The kits are installed as follows:
1. Remove all filters, filter racks and brackets. Save all
screws. Discard bracket end.
2. Attach top duct collar in conjunction with top filter rack
with truss head screws.
3. Attach bottom duct collar and filter rack.
4. On single compressor units, attach two flanges using four
(4) #8 truss head screws provided.
5. Attach center support in original location.
6. Locate and attach center filter racks using screws pro-
vided.
7. Attach duct collar sides using eight (8) #10 sheetmetal
8. No point in the drain system may be above the drain
connection of any unit.
9. Automatic flow controlled devices must not be installed
prior to system cleaning and flushing.
10. A high point of the piping system must be vented.
11. Check local code for the need of dielectric fittings.
Figure 8. Assembly detail
Filter
Rack
Duct
Collar
Duct Collar Side
Figure 9.
Page 6 of 24 / IM 439
Chassis
Center Support
Side Flanges
Door End
Top Duct Collar
Duct Collar Side
Top Filter Rack
Center Filter Racks
Filters
Piping
CAUTION
!
Do not overtorque fittings. The maximum torque without
damage to fittings is 30 foot pounds. If a torque wrench is not
available, use as a rule of thumb, finger-tight plus one
quarter turn. Use two wrenches to tighten the union, one to
hold the line and one for simultaneous tightening of the nut.
1. All units are recommended to be connected to supply and
return piping in a two-pipe reverse return configuration. A
reverse return system is inherently self-balancing and requires only trim balancing where multiple quantities of units
with different flow and pressure drop characteristics are
connected to the same loop. A simple way to check for
proper water balance is to take a differential temperature
reading across the water connections. To insure proper
water flow, the dif ferential should be 10°F to 14°F (5°C to
8°C) in the cooling mode of operation.
A direct return system may also be made to work acceptably , but proper water flow balancing is more difficult
to achieve and maintain, and may require flow control
devices.
2. The piping can be steel, copper or PVC.
3. Supply and return runouts are usually connected to the
unit by short lengths of high pressure flexible hose which
are sound attenuators for both unit operating noise and
hydraulic pumping noise. One end of the hose should have
a swivel fitting to facilitate removal for service. Hard piping can also be brought directly to the unit although it is
not recommended since no vibration or noise attenuation
can be accomplished. The hard piping must have unions
to facilitate unit removal
setup)
.
(see Figure 10 for typical piping
Figure 10.
Branch
Duct
Trunk Duct
4. Supply and return shutoff valves are required at each conditioner. The return valve is used for balancing and should
have a “memory stop” so that it can always be closed off
but can only be reopened to the proper position for the flow
required.
5. No unit should be connected to the supply and return piping until the water system has been cleaned and flushed
completely. After the cleaning and flushing has taken place,
the initial connection should have all valves wide open in
preparation for water system balancing.
6. Condensate piping can be steel, copper or PVC. Each
unit is supplied with a FPT threaded fitting.
7. The condensate disposal piping must have a trap and the
piping must be pitched away from the unit not less than
1
⁄4" per foot (21 mm per meter). Generally , the condensate
trap is made of copper. A complete copper or PVC condensate system can also be used. Union fittings in the copper
lines should be applied to facilitate removal.
8. No point in the drain system may be above the drain connection of any unit.
9. Automatic flow controlled devices must not be installed
prior to system cleaning and flushing.
10. A high point of the piping system must be vented.
11. Check local code for the need of dielectric fittings.
Cleaning and Flushing
System
1. Prior to first operation of any conditioner, the water cir-
culating system must be cleaned and flushed of all construction dirt and debris.
If the conditioners are equipped with water shutoff
valves, either electric or pressure operated, the supply and
return runouts must be connected together at each conditioner location. This will prevent the introduction of dirt
into the unit. Additionally, pressure operated valves only
open when the compressor is operating
(see Figure 1 1)
.
Transition
Duct
Flexible
Connector
Main
Duct
Flexible Hose
with Brass
Pipe Fittings
Supply
Return
Balancing
Valve with
Close-off
Condensate
Figure 11.
Return Runout
Supply Runout
Rubber Hose
Runouts Initially
Connected Together
Mains
IM 439 / Page 7 of 24
Cleaning and Flushing System (Continued)
2. The system should be filled at the city water makeup
connection with all air vents open. After filling, vents should
be closed.
The contractor should start main circulator with pressure reducing valve makeup open. Vents should be
checked in sequence to bleed off any trapped air to assure circulation through all components of the system.
Power to the heat rejector unit should be off, and the
supplementary heat control set at 80°F (27°C).
While circulating water, the contractor should check
and repair any leaks in the piping. Drain at the lowest
point(s) in the system should be opened for initial flush
and blowdown, making sure city water fill valves are set
to make up water at the same rate. Check the pressure
gauge at pump suction and manually adjust the makeup
to hold the same positive steady pressure both before
and after opening the drain valves. Flush should continue for at least two hours, or longer if required, to see
clear, clean drain water.
3. Supplemental heater and circulator pump should be shut
off. All drains and vents should be opened to completely
drain down the system. Short circuited supply and return runouts should now be connected to the conditioner
supply and return connections. Teflon tape is recommended over pipe dope for pipe thread connections. Use
no sealers at the swivel flare connections of hoses.
4. Trisodium phosphate was formerly recommended as a
cleaning agent during flushing. However, many states
and localities ban the introduction of phosphates into their
sewage systems. The current recommendation is to simply flush longer with warm 80°F (27°C) water.
5. Refill the system with clean water. Test the litmus paper
for acidity, and treat as required to leave the water slightly
alkaline (pH 7.5 to 8.5). The specified percentage of antifreeze may also be added at this time. Use commercial
grade anti-freeze designed for HVAC systems only. Do
not use automotive grade anti-freeze.
6. Set the system control and alarm panel heat add setpoint
to 70°F (21°C) and the heat rejection setpoint to 85°F
(29°C). Supply power to all motors and start the circulating pumps. After full flow has been established through
all components including the heat rejector (regardless of
season) and air vented and loop temperatures stabilized,
each of the conditioners will be ready for check, test and
start-up and for air and water balancing.
Start-up
1. Open all valves to full open position and turn on power to
the conditioner.
2. Set thermostat for Fan Only operation by selecting Off at
the system and On at the fan switch. If Auto fan operation
were selected, the fan would cycle with the compressor.
Check for proper air delivery.
3. All units have variable pitch motor sheaves. Reset for
correct airflow.
4. Set thermostat to Cool. If the thermostat is an automatic
changeover type, simply set the cooling temperature to
the coolest position. On manual changeover types additionally select Cool at the system switch.
Again, many conditioners have time delays which
protect the compressor against short cycling. After a few
minutes of operation, check the discharge grilles for cool
air delivery. Measure the temperature difference between
entering and leaving water. It should be approximately
1
1
⁄2 times greater than the heating mode temperature
difference. For example, if the cooling temperature difference is 15°F (8°C), the heating temperature difference
should have been 10°F (5°C).
Without automatic flow control valves, a cooling temperature difference of 10°F to 14°F (5°C to 8°C) is about
right. Adjust the combination shutoff/balancing valve in
the return line to a water flow rate which will result in the
10°F to 14°F (5°C to 8°C) degree difference in cooling.
5. Set thermostat to Heat. If thermostat is the automatic
changeover type, set system switch to the Auto position
and depress the heat setting to the warmest selection.
Some conditioners have built-in time delays which prevent the compressor from immediately starting. With
most control schemes, the fan will start immediately.
After a few minutes of compressor operation, check for
warm air delivery at discharge grille. If this is a “cold
building” start-up, leave unit running until return air to the
unit is at least 65°F (18°C).
Measure the temperature difference between entering and leaving air and entering and leaving water. With
entering water of 60°F to 80°F (16°C to 27°C), leaving
water should be 6°F to 12°F (3.3°C to 6.6°C) cooler, and
the air temperature rise through the machine should not
exceed 35°F (19°C). If the air temperature exceeds 35°F
(19°C), the airflow rate is probably inadequate.
If the water temperature difference is less than 6°F
(3.3°C) degrees, the water flow rate is excessive. If the
water temperature difference exceeds 12°F (6.6°C), then
the water flow rate is inadequate.
6. Check the elevation and cleanliness of the condensate
line. If the air is too dry for sufficient dehumidification,
slowly pour enough water into the condensate pan to
ensure proper drainage.
7. If the conditioner does not operate, the following points
should be checked:
a. Is proper voltage being supplied to the machine?
b. Is the proper type of thermostat being used?
c. Is the wiring to the thermostat correct?
8. If the conditioner operates but stops after a brief period,
check for:
a. Is there proper airflow? Check for dirty filter, incorrect
fan rotation (3-phase fan motors only), or incorrect
ductwork.
b. Is there proper water flow rate within temperature limits?
Check water balancing; backflush unit if dirt-clogged.
9. Check the unit for vibrating refrigerant piping, fan wheels,
etc.
10. Do not lubricate the fan motor during the first year of
operation as it is prelubricated at the factory.
Page 8 of 24 / IM 439
Loading...