McQuay ALP-159A Maintenance Manual
BULLETIN NO. IM
173
JULY 1978
INSTALLATION AND
MAINTENANCE DATA
PACKAGED AIR COOLED CONDENSING UNIT
TYPE ALP-067A THRU 159A
GROUP McQUAY-PERFEX Inc. 13600 Industrial Park Blvd., P.O. Box 1551, Minneapolis, Mn. 55440
@)
NOTICE:
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.
CAUTION:
Sharp edges and coil surfaces are a potential
injury hazard.
Avoid contact.
page
2
Nomenclature
PROPELLER FANS
LOW POWER CONSUMING
AIR COOLED CONDENSER
AL
-
089 A D
REFRIGERANT CIRCUITS
(D=Dual;
S=Single)
DESIGN VINTAGE
NOMINAL CAPACITY (TONS)
Inspection
When the equipment is received,
all items should be carefully checked
against the bill of lading to insure a complete shipment.
All units
should be carefully inspected for damage upon arrival.
All shipping
damage should be reported to the carrier and a claim should be filed.
The unit serial plate should be checked before unloading the unit to
be sure that it agrees with the power supply available.
INSTALLATION
Handling
Care should be taken to avoid rough handling or shock due to dropping
the unit.
Do not push or pull the unit from anything other than the
base,
and block the pushing vehicle away from the unit to prevent
damage to the sheet metal cabinet.
(See Figure 1.)
FIGURE 1
SUGGESTED PUSHING ARRANGEMENT
GOOD PUSHING ARRANGEMENT
CABINET DAMAGE UNLIKELY
POOR PUSHING ARRANGEMENT
CABINET DAMAGE LIKELY
page
4
Never allow any part of the unit to fall during unloading or moving
as this may result in serious damage.
To lift the unit,
2+"
diameter lifting holes are provided in the base
of the unit.
Spreader bars and cables should be arranged to prevent
damage to the condenser coils or unit cabinet.
(See Figure 2.)
FIGURE 2
TABLE 1
SUGGESTED LIFTING ARRANGEMENT
SPREADER BAR
REQD.
-MUST USE THESE RIGGING HOLES
(N
OTE
CONTROL 60x
L~cATI~NI
SHIPPING WEIGHTS
ALP UNIT SIZE
UNIT WEIGHT
(Ibs)
067ASlD
4125
078ASlD
4308
089A
4963
106A
5134
ALP UNIT SIZE
126A
136A
149A
159A
UNIT WEIGHT
(Ibs)
6021
6095
6873
7202
Location
Due to the vertical condenser design, it is recommended that certain
precautions be taken before installation to orient the unit so that
prevailing winds blow parallel to the unit length thus minimizing
effects on condensing pressure.
If it is not practical to orient
the unit in this manner,
a wind deflecting fence should be consi-
dered.
It is also necessary to provide adequate clearance on all sides of
the unit for service access and satisfactory performance.
At least
60 in.
(1 fan diameter) should be allowed on each side of the unit
for condenser air inlet and compressor removal on units 067
&
078.
If parallel units are installed side by side, 120 in. should be allowed between units.
This will prevent excessive condensing temper-
atures and enhance system performance and operating economy.
Clear-
ance for service access should be at least 78 in. at the control cen-
ter end for compressor removal on units 089 through 159 and 42 in.
on units 067 and 078.
Allow 36 in.
clearance at the end opposite
the control center for ease of access to bearings and drives.
These
clearances are illustrated in Figure 3.
page 5
FIGURE 3 CLEARANCE AROUND UNIT
t
60” MINIMUM CLEARANCE (2)
60”
MINIMUM
CLEARANCE
(2)
NOTE:
(I)
Minimum vertical clearance above unit should be 10
feet.
(2) Clearance to condenser coil must be increased if more
than one side is obstructed or between adjacent units.
Consult your
McQUAY
sales representative.
Service Access
Each end of the unit must be accessible after installation for peri-
odic service work.
Compressors and manual liquid line shutoff valves
are accessible from the control center end of the unit through re-
movable access panels on unit sizes 089 through 159 and hinged side
access doors on unit sizes 067 and 078.
All operational, safety,
and starting controls are located in the unit control center.
They
are protected by a keylocked,
weatherproof enclosure which contains
internal"dead front"
doors for protection of service personnel from
high voltage starting controls while servicing low voltage operational controls.
All resettable or adjustable controls are located
just below the main control center.
There is one resettable control
enclosure on each side of the unit and each enclosure contains con-
trols for compressors on that side of the unit.
Capped connections
for field service gauges are also located inside these enclosures.
In addition,
each of these enclosures are removable to improve access
to compressors for field replacement.
The condenser fans, motors,
and drives are accessible through a walk-
in,
keylocked access door.
The access door is located at the end of
the unit opposite the control center.
An internal fan guard is located below the condenser fans and drives
on units 089 through 159.
This guard must be removed to service the
fan drives but MUST always be reinstalled when service work is com-
plete.
On unit sizes 067 and 078,
an interlock switch kills power to conden-
ser fans whenever the door is opened for service work on fans or
drives.
CAUTION:
Disconnect all power to the unit while servicing condenser
fan drives.
page
6
Vibration Isolators
Vibration isolators are recommended for all roof mounted installa-
tions or wherever vibration transmission is a consideration.
Table
2 lists spring isolators for all ALP unit sizes.
Figure 4 shows
isolator locations in relation to the unit control center.
Figure 5
gives dimensions that are required to secure each
McQuay
isolator
selection to the mounting surface.
Table 3 shows the isolator loads at each location shown in Figure 4
and the maximum loads for each McQuay selection.
TABLE 2
VIBRATION
ISOLATORS
216404B-27 2164046-26
TABLE 3
IS0 LATOR LOADS
page 7
REFRIGERANT PIPING
General
McQuay type ALP condensing units are adaptable to either chilled
water or air handling air conditioning applications.
The only restriction on applications is that the evaporator be selected for a
system using refrigerant 22.
Evaporator Above Condensing Unit
Figure 6 shows an installation where the evaporator is installed
above the condensing unit.
It is shown for an air handling installation but all components shown are recommended for chilled water
installations except that a refrigerant distributor is not usually
required for shell-and-tube evaporators.
FIGURE 6
EVAPORATOR ABOVE CONDENSING UNIT
Legend
a
Filter-drier
b
Solenoid valve
:
Sight-glass/moisture indicator
Thermal expansion valve
e
Suction line, pitched toward compressor
f
Liquid line
9
Vibration absorber
Notes:
1. Piping shown is for one circuit only, second circuit is similar.
2. All piping & piping components are by others.
Evaporator Below Condensing Unit
Figure 7 shows an installation where the evaporator is installed be-
low the condensing unit.
It is shown for an air handling installation but all components shown are recommended for chilled water installations except that a refrigerant distributor is not usually re-
quired for shell-and-tube evaporators.
Mote that a double suction
riser is shown for this arrangement.
Risers
"A + B" are sized so that their combined cross-sectional internal area will allow full load unit operation without excessive
pressure drop (see notes, Table 4).
Riser
"B"
is sized to provide
adequate suction gas velocity for proper oil return at minimum load
conditions.
This riser becomes effective only when the trap shown
in riser "A"
fills itself with oil.
It should be emphasized that
the trap shown in riser "A"
should be designed to contain a minimum
internal volume to keep the total system oil requirements at a mini-
mum.
Table 4 gives recommended line sizes for both single and double
suction lines and for liquid lines.
page
9
Figure 9 shows typical field wiring that is required for unit instal-
lation.
Items that require field wiring are:
liquid line solenoids
(SVl & SV2),
optional hot gas bypass solenoid
(SV5)
and the cooling
thermostat as well as the unit power supplies.
FIGURE 9
TYPICAL FIELD WIRING
PBl
DISCONNECT
UNIT MAIN
BY OTHERS--\,,< TERMINAL BLOCK
3pH ---_H
___
POWER
___/-:__
CONI, llNlT
COMPRESSORS
c
AND FAN MOTORS
;BK
SuppLy
_ _
__I’_
-
-
WH
I
\
SEPARATE
II?,“-IOA
LEGEND
POWER FOR CONTROLS
I
‘,‘--
DISCONNECT BY OTHERS
OPTIONAL
FdSEU
i g_ ~~~SLT~OM~~~,~~NNECTION
01
8
A
NOTE
I
TRANSFORMER
FUSE-IO A
0 II
-FLOW SWITCH
(C.W.
SYSTEMS)
irJH_WHlTt
WlhlNG
fNEUT1.
SVl,2-LIOUID ’ INE
SOL. VALVE
REFRIGERANT CIRCUIT I
SAFETY AND OPERATING
SVS-HOT
GAS BY PASS
CONTROLS
SOL VALVE
R3,4-COMP.
384 START
TIME
CLOCK;;-
RELAYS
R5,6,7,E
-SAFETY
RELAYS
PSI.2 -PUMPDOWN
SWITCHES
TDl1,12,13-COMP
SEOUEN-
CING TIME DELAYS
Rx-EVAP. FAN INTERLOCK
PREVENTS OPENING
SV’S WITHOUT LOAD
RELAYS PROVIDE
RECYCLING PUMP
DOWN DURING OFF
SEASON
REFRIGERANT CIRCUIT
2
SAFETY AND OPERATING
CONTROLS
UNIT CONDENSER
FANS
OPERATING CONTROLS
POWER SUPPLY
FOR CONTROLS
’
I
1
I
I
I
PUMP STARTER
PUMP STARTER
CIRCUIT
R9
RIO
NOTE; CIRCUIT SHOWN ASSUMES CONTINUOUS
6
6
T
-C
PUMP
OPERATIIN~FOR
INTERMITTENT
CC. W.
SYSTEMS1
a0 __:
I I
1
PUMP OPERATION CONSULT
McOUAY
I I
I
Thermostat Wiring
Since it is impossible for
McQuay to anticipate the type of installa-
tion that an ALP condensing unit may be used on, we do not factory
install a thermostat.
We do,
however,
provide numbered terminals in-
side the unit control center to which a thermostat may be connected.
These terminals are shown and labeled "Terminals For Thermostat" on
the electrical schematics.
On a two circuit unit it is important to connect the thermostat so
that as successive stages of cooling are called for, the compressors
in the unit will be started to alternately increase the condenser
load from refrigerant circuit 1 to circuit 2.
This is illustrated
in Table 9.
Figure 10 shows how to install 2 independent four stage
thermostats for controlling an 8 stage unit and Figure 11 shows typical field wiring for an 8 stage thermostat.
page 14
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