McQuay ALP-027C Installation Manual
Table of Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...3
Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...3
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...3
Installation
Rigging and moving units . . . . . . . . . . . . . . . . . . . . . ...3
Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...3
Refrigerant Piping
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...4
Recommended piping arrangements . . . . . . . . . . . . ...5
Recommended line sizes . . . . . . . . . . . . . . . . . . . . . ...5
Hot gas bypass components. . . . . . . . . . . . . . . . . . ...6
Refrigerant piping connections . . . . . . . . . . . . . . . . . ...6
Holding charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...6
Leak Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...6
Evacuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...6
Charging the system . . . . . . . . . . . . . . . . . . . . . . . . . ...7
Refrigerant charge . . . . . . . . . . . . . . . . . . . . . . . . . . ...7
Pressure-vacuum equivalents . . . . . . . . . . . . . . . . . . ...7
Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...7
Vibration isolators . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...8
Physical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...9
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...10
Field Wiring
Typical field diagram . . . . . . . . . . . . . . . . . . . . . . . . ...11
Control center layout and operation . . . . . . . . . . . . ...12
Recommended disconnect location . . . . . . . . . . . . ...12
Electrical legend . . . . . . . . . . . . . . . . . . . . . . . . . . . ...12
Electrical Hook-up . . . . . . . . . . . . . . . . . . . . . . . . . . . ...12
Normal Sequence of Operation
Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...13
Pumpdown cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . ...13
Start-up&Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
System Maintenance
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...14
Fan shaft bearings . . . . . . . . . . . . . . . . . . . . . . . . . ...14
Electrical terminals . . . . . . . . . . . . . . . . . . . . . . . . . ...14
Compressor oil level . . . . . . . . . . . . . . . . . . . . . . . . ...14
Condensers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...14
Refrigerant sightglass . . . . . . . . . . . . . . . . . . . . . . . ...14
Service
Thermostat expansion valve... . . . . . . . . . . . . . . . ...15
Filter driers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...15
Liquid line solenoid valve.... . . . . . . . . . . . . . . . . ...15
In-Warranty Return Material Procedure . . . . . . . . . ...15
Appendix: Standard Controls
High pressure control . . . . . . . . . . . . . . . . . . . . . . . ...16
Low pressure control . . . . . . . . . . . . . . . . . . . . . . . . ...16
Compressor lockout . . . . . . . . . . . . . . . . . . . . . . . . ...16
Compressor motor protector . . . . . . . . . . . . . . . . . . ...16
FanTrol head pressure control. . . . . . . . . . . . . . . . . ...16
Oil pressure safety control . . . . . . . . . . . . . . . . . . . ...16
Appendix: Optional Controls
SpeedTrol head pressure control . . . . . . . . . . . . . . ...17
Low ambient start . . . . . . . . . . . . . . . . . . . . . . . . . . ...17
High ambient control . . . . . . . . . . . . . . . . . . . . . . . . ...17
Part winding start . . . . . . . . . . . . . . . . . . . . . . . . . . ...17
Phase/voltage monitor . . . . . . . . . . . . . . . . . . . . . . . ...17
Hot gas bypass (field installed) . . . . . . . . . . . . . . . ...18
VAV direct expansion systems . . . . . . . . . . . . . . . . ...18
ALP Controls, Settings & Functions . . . . . . . . . . . . ...19
Troubleshooting Chart . . . . . . . . . . . . . . . . . . . . ...20.21
Product Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . ...22
‘“McQuay” and “SeasonCon” are registered tradenames of SnyderGeneral Corporation. “FanTrol” and “SpeedTrol” are tradenames of SnyderGenera! Corporation.
01994 SnyderGeneral Corporation. All rights reserved throughout the world.
“Bulletin illustrations cover the general appearance of SnyderGeneral Corporation products at the time of publication
and we reserve the right to make changes in design and construction at any time without notice.”
Page2/lM404
Introduction
Model type ALP air cooled condensing units are designed
for outdoor installations and are compatible with either air
handling or chilled water systems. Each unit is completely
assembled and factory wired before evacuation, charg-
ing and testing. Each unit consists of an air cooled condenser
with integral subcooler section with complete discharge piping and suction and liquid connections for connection to any
air or water cooling evaporator.
Inspection
When the equipment is received, all items should be carefully rier and a claim should be filed. The unit serial plate should
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 car-
be checked before unloading the unit to be sure that it agrees
with the power supply available.
Installation
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. Caution: Sharp edges and coil surfaces area potential injury hazard.
Avoid contact with” them.
Rigging and Moving Units
The exact method of handling and setting the unit depends
on available equipment, size of unit, final location, and other
variables. It is therefore up to the judgment of the riggers and
movers to determine the specific method of handling each
unit.
All units are equipped with built-in skids for rigging and
moving.
Figure 1. Suggested rigging
Location
Due to vertical condenser design, it is recommended that the
unit is oriented so that prevailing winds blow parallel to the
unit Iength, thus minimizing effects on condensing pressure.
If it is not practical to orient the unit in this manner, a wind
deflector should be constructed.
Units are designed for outdoor application and may be
mounted on a roof or concrete slab (ground level installation).
Roof-mounted units should be installed level on steel channels or an l-beam frame to support the unit above the roof.
The roof must be strong enough to support the weight of
the unit. See Physical Data for unit weight. Concrete slabs
used for unit mounting should be installed level and be properly supported to prevent settling. A one-piece concrete slab
with footings extended below the frost line is recommended.
Figure 2. Clearance around unit
t
5 Ft. Min. Clearance
For Air Inlet
&u
COND. COIL
Min. r- =
4 Ft.
Clearance ~ g
For Service
“o”
rcp
COND. COIL
Ft. Min. Clearance
5
For Air
COMP. Clearance
Inlet
6 Ft. Min.
For Service
NOTES
1. Minimum clearance between units is 12 feet.
2. Units must not be Installed in a pit that is deeper than the height of the unit.
3. Minimum clearance on each side is 12 feet when installed in a pit.
IM 404 I Page 3
Refrigerant Piping
General
Piping design, sizing and installation information presented
in ASHRAE Handbooks should, where applicable, be followed
in the design and installation of piping. 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 R-22.
Refrigerant Piping
Piping between the condensing unit and the cooling coil must
be designed and installed to minimize pressure drop, prevent liquid refrigerant carryover to the compressor and to
assure a continuous return of compressor oil from the system.
Piping sketches and tables are not intended to provide information on all of the possible arrangements.
Piping recommendations include:
1.
The use of type K or L clean copper tubing. All joints should
be thoroughly cleaned and brazed with high temperature
solder.
2.
Piping sizes should be based on temperature/pressure
limitations as recommended in the following paragraphs.
Under no circumstances should pipe size be based upon
the coil or condensing unit piping connection size.
3.
Suction line piping pressure drop should not exceed the
pressure equivalent of 2° F (3 psi) per 100 feet of equivalent
pipe length. After the suction line size has been determined, the vertical suction risers should be checked to
verify that oil will be carried up the riser and back to the
compressor. The suction line should be pitched in the
direction of refrigerant flow and adequately supported.
Lines should be free draining and fully insulated between
the evaporator and the compressor. Table 3 shows piping information for units operating at suction temperatures
between 40F and 45F and a condenser entering air
temperature of 95° F. If operating conditions are expected
to vary substantially from these operating levels, the pipe
sizing should be rechecked.
4.
Vertical suction risers should be checked using Table 1
to determine the minimum tonnage required to carry oil
up suction risers of various sizes.
The Iiquid line should be sized for a pressure drop not to
5.
exceed the pressure equivalent of 2° F (6 psi) saturated
temperature. The liquid line on all units must include a
liquid solenoid valve wired into the circuit as shown on the
applicable unit wiring diagrams.
The control circuit for all compressors has been de-
signed to include a pumpdown cycle. The use of a liquid
line solenoid is required for proper unit operation. In ad-.
dition, a filter-drier should be located between the liquid
line service valve
and the solenoid valve and a combina-
tion moisture indicator/sightglass should be located in the
liquid line ahead of the expansion valve.
Suggested piping arrangements are shown on page 5. The
6
figures shown are for an air handling installation, but all
components shown are recommended for chilled water
vessel installations except that a refrigerant distributor is
not usually required for shell-and-tube evaporators.
If dual suction risers are used:
7
Double risers are sized so that the combined crosssectional internal area will allow full load unit operation
without excessive pressure drop (see notes, Table 3). Riser
“A” 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 “B”
fills itself with oil. It should be emphasized that the trap
shown in riser “B” should be designed to contain a
minimum internal volume to keep the total system oil requirements at a minimum. Table 3 gives recommended
line sizes for both single and double suction lines and for
Iiquid lines,
a.
‘ The combined cross-sectional areas of the two risers
must be capable of maintaining adequate refrigerant
velocity for oil return at full unit tonnage.
b.
The extra riser should be of a smaller diameter than
the main riser. The extra riser must include its own trap
at the bottom and should enter the main suction header
at twelve o’clock.
The trap serving the extra riser must be as short as fit-
c.
tings permit. A “U” fitting or the combination of a 90’
standard “L” and a 90° street-L is recommended.
d.
The suction line Ieaving the coil should also include a
trap if the expansion valve control bulb is to be on the
horizontal section leaving the coil outlet. See the piping sketches on page 5.
Table 1. Minimum
tonnage (R-22) to carry oil up
suction riser at 40” F saturated suction.
Line Size OD 1%
Min. Tons 1.50 2.50 3,80
NOTE: When compressor minimum tonnage is less than shown in the above
table for a given line size. double suction risers will
1
7.60 13.10 20.4
21A 2% 3~/’E 378
1 ye
3/3
4y~
29.7 41.3
be required
Table 2. Equivalent feet of straight tubing for copper fittings and valves
7/8
0,9
1%
1.7
2.1 3.0 3.4
1.7
2.6 3.3
29
1.0
12
ELBOWS
900 Standard
90° Long Radius
900 Street
45o Standard
45” Street
180° aEND
TEES
Full Size
Reducing
VALVES
Globe Valve, Open
Gate Valve, Open
Angle Valve, Open
FITTING TYPE
5/8
I
1.6 2.0 2.6 3.3
1.0 1.4
2.5 3.2 4.1 5.6 6.3
0.6 0.9 1.3 1.7 2.1
1.3 1.5
2.5 .3.2 4.1 5.6 6.3 8.2
1.0 1.4
1.6 2,0
16 22
0.7
7.0 9.0
Page 4 I IM 404
1ye 1ya 2Y8
4.0
2.3 2,6 3.3
2.3 2.6 3.3
4.0 5.0 6.0
38 43 55
1.5 1.8
15 18
5.0
8.2
2.6 3.2
4.5 5.2
2.3 2.8 3.2 4.0
24 29 35 41
25A 3~/4
6.0
4.1 5.0
10.0 12.0 15.0 17.0
10.0
4.1 5.0
69 84 100
7.5
4.0
6.4 7.3 8.5
12.0
7.5
378
I
9.0
5.9
4.7 5.2
15.0
5.9
9.0
49A
10.0
6.7
17.0
6.7
10.0
I
120
4.5
47
.
I
Table 3. Recommended line eizes
ALP UNIT 0.0. COPPER
SIZE
!
027C
032C
037C
041C
)
NOTES:
Recommended line sizes shown in the above table are based on the unit
operating conditions between 40° F and 45” F saturated suction temperature
and condenser entering air temperature of 95” F, per 100 ft. equivalent length
of tubing. When design conditions vary, the table values should be rechecked.
Liquid and suction lines based on a recommended equivalent pressure
1.
drop of 2F (3 psi for suction line, 6 psi for liquid line) per 100 ft. of
equivalent length.
When refrigerant required to charge a circuit exceeds the pumpdown
2.
capacity of that circuit the use of a separate refrigerant storage receiver
will be required. The pumpdown capacity is based on the condenser
full at 90iF (see Physical Data).
3.
Wherever vertical rise occurs in the suction piping, the minimum tonnage
for oil entrainment should be checked and where necessary double suction risers should be utilized. See Table 1.
4.
Wherever vertical rise occurs in the suction piping on a system with hot
gas bypass, double suction risers may not be needed as the velocity of
suction gas is increased at minimum load conditions.
5.
Total equivalent feet for a given piping layout must include the equivalent
length of straight pipe for fittings, valves and specialties added to the total
run of straight pipe.
Piping design, sizing and installation information presented in ASHRAE
6.
Handbooks should, ‘where applicable, be followed in the design and installation of piping.
DOUBLE
A–B
134 — lye 21A
1% — 1% 2% 1~~
SINGLE
lye — 21A 2%
lye — 21A 2’% 1ye
SUCTIONLINESIZE
LIQUID LINE
SIZE
O.D. COPPER
11A
l%
90%
Table 4. Weight of refrigerant R-22 in copper lines
(pounds per 100 feet of type L tubing)
0.0.
Vol.per
Line 100 Ft. Llquld
in Cu. Ft. r@lOO”F
Size
0.054 3.64
%
V2 0.100 7.12 .374
0.162 7.12 .605 .156
%
0.336
‘h
11A 0.573 40.8 2.14
Weight of Refrigerant, Lbe.
Hot Gas
@120”F (Superheated to 65” F)
Cond. 20” F 40” F
.202
24.0 1.26
.052 .077
.096
.323
.550
Suction Gas
1% 0.672 62.1 3.26 .639 1.250
1% 1.237 86.0
2% 2.147 153.0 6.04 2.06 3.060
2% 3.312 236.0
3%
3y,
4j~ 6.313 592.0 31.1 8.00 11.190
t
4.726
6.398I456.0 24.0
I
336.0
4.62
12.4
17.7
1.190 1.770
3.16
4.55 6.750
6.15
.143
.232
.460
.620
4.720
9.140
I
Figure 3. Typical refrigerant piping diagram
Evaporator or cooler
below condensing unit
AIR FLOW
Evaporator or cooler
ab
I
LEGEND
a Filter-drier
b Solenoid valve
c 8ightglass/moisture indicator
d Thermal expansion valve
e Suction line, pitched toward compressor
f Liquid line
g Vibration absorber
A & B Double suction riser (see Note 2)
NOTES:
1. All piping and piping components are by others.
2. Trap for double suction riser should be as small in the horizontal direction as fittings will allow.
3. Cooler suction connection should always be top connection.
lM 404 I Page 5
Figure 4. Recommended liquid line piping
CONDENSING UNIT
SEALED CORE
FILTER DRIER
LIQUID LINE
\/
BALL VALVES TO ISOLATE
FILTER DRIER FOR SERVICE
Hot Gas Bypass Components
Hot gas bypass kits are available for each ALP unit size. Each
kit includes a solenoid valve, a hot gas bypass valve and instruction drawing. See page 20 for hot gas bypass operation.
Table 5. Hot gas bypass kits
ALP UNIT
SIZE
027C
032C
037C
041 c 886-580898A-04
y.
KIT NUMbER
886-580898A-03 1ye
886-580898A-04 1ye
888-580898A-03 1ye
LINE SIZE
O.D. (IN.)
1ye
Refrigerant Piping Connections
Refrigerant piping connections will be made at the compressor end of the unit. Suction and liquid lines should be
routed through the compressor enclosure on the side of the
unit.
Holding Charge
The Model ALP condensing unit is shipped with a holding
charge of refrigerant. At the time the unit was received a visual
inspection of the unit piping should have been made to be
sure no breakage had occurred or that fittings might have
been loosened. A pressure check should indicate a positive
pressure in the unit. If no pressure is evident, the unit will
have to be leak tested and the leak repaired. This should be
noted and reported to your sales representative or freight carrier if the loss is due to shipping damage.
Leak Testing
In the case of loss of the refrigerant holding charge, the unit
should be checked for leaks prior to charging the complete
system. If the full charge was lost, leak testing can be done
by charging the refrigerant into the unit to build the pressure
to approximately 10 psig and adding sufficient dry nitrogen
to bring the pressure to a maximum of 125 psig. The unit
should then be leak tested with a Halide or electronic leak
detector. After making any necessary repair, the system
should be evacuated as described in the following paragraphs.
Caution: Do not use oxygen to build up pressure. A serious
explosion could be the result.
Evacuation
After it has been determined that the unit is tight and there
are no refrigerant leaks, the system should be evacuated.
The use of a vacuum pump with a pumping capacity of approximately 3 cu. ft./rein. and the ability to reduce the vacuum
in the unit to at least 1 millimeter (1000 microns) is recommended.
LIQUID LINE
SOLENOID
AIR HANDLER
u
r “n\”
SIGHTGLASS
EXPANSION
VALVE
1. A mercurv manometer, electronic or other type of micron
gauge should be connected to the unit at a-point remote
from the vacuum pump. For readings below 1 millimeter,
an electronic or other micron gauge should be used.
2. The triple evacuation method is recommended and is particularly helpful if the vacuum pump is unable to obtain
the desired 1 millimeter of vacuum. The system is first
evacuated to approximately 29 inches of mercury. Enough
refrigerant vapor is then added to the system to bring the
pressure up to O pounds.
3. Then the system is once again evacuated to 29 inches
of vacuum. This procedure is repeated three times. This
method can be most effective by holding system pressure
at Opounds for a minimum of 1 hour between evacuations.
The first pull down will remove about 90% of the noncondensables, the second about 90% of that remaining
from the first pull down and after the third only 1/10 of 1%
noncondensables will remain.
Table 6 shows the relationship between pressure, microns,
atmospheres, and the boiling point of water.
Charging the System
After all refrigerant piping is complete and the system has
1.
been evacuated, it can be charged as described in the
paragraphs following. Connect the refrigerant drum to the
gauge port on the liquid line and purge the charging line
between the refrigerant cylinder and the valve. Then open
the valve to the mid-position.
2.
If the system is under a vacuum, stand the refrigerant drum
with the connection up and open the drum and break the
vacuum with refrigerant gas.
3.
With a system gas pressure higher than the equivalent
of a freezing temperature, invert the charging cylinder and
elevate the drum above the condenser. With the drum in
this position, valves open and liquid refrigerant will flow
into the condenser. Approximately 75% of the total requirement estimated for the unit can be charged in this manner.
After 75% of the required charge has entered the con-
4.
denser, reconnect the refrigerant drum and charging line
to the suction side of the system. Again purge the connecting line, stand the drum with the connection up, and
place the service valve in the open position.
Important: At this point charging procedure should be in-
terrupted and prestart checks made before attempting to com-
plete the refrigerant charge (see start-up procedures).
Itis recommended that the total operating charge
Note:
be stamped on the with nameplate for future reference.
Page 6 I IM 404
Refrigerant Charge
Each ALP condensing unit is designed for use with R-22. See
physical data for approximate refrigeration charges for operation of the unit. Additional refrigerant will be needed for the
system piping and evaporator. Estimated total operating
charge should be calculated before charging system.
Table 6. Pressure-vacuum equivalents
ABSOLUTE PRESSURE ABOVE ZERO
MICRONS PSIA
o
50 0.001 759.95
100 0.002
150 0.003 759,85
200 0.004
300 0.006 759,70
500 0.009 759.50
1,000 0.019
0
2,000 0.039
4,000 0.078
VACUUM BELOW ONE ATMOSPHERE APPROXIMATE
MERCURY MERCURY FRACTION OF
(mm)
760,00
759.90 29.920
759.80 29.910
759.00 29.880
758.00 29.840
756.00 29.760
6,000 0.117 754.00
6,000
10,000 0.193
15,000 0.290
20,000 0.387
30,000 0.580
50,000 0.967
100,000 1.930
200,000 _—..500,000
760,000 14.697
0.156
1
3.870 560.00
9.670
I
752.00 29.600
750.00 29.530
745.00
740.00 29130 1/38
730.00
710.00
660.00 25.960
260.00 10.240
0 0 1 Atmosphere
Caution: Tots/ operating charge shou/dnot exceed the
condenser pumpdown capacity plus the capacity of the liquid
Iine. A liquid receiver should be used if the unit operating
charge exceeds the pumpdown capacity. Refer to the
ASHRAE Handbook for the design and installation of piping
and components.
BOILING POINT
(Inches)
29.921
29.920 1/15,200
29.920
29.910 1/2,500
29,900
ONE ATMOSPHERE PRESSURE (’F)
.
1/7,600 — 40
1/5,100 — 33
1/3,800 — 28
1/1,520 — 12
OF H,O AT EACH
—
— 50
— 21
1/760 1
11380 15
1/189 29
29.690
I
29.330
28.740
27.950
22.050 1/4 157
1/127 39
1/95
I
1/76 52
1/50
I
1/25 64
1/15 101
2115 125
2/3 192
I
I
I
,
I
46
63
7? I
---
212
i
Figure 5.
ALP-027C thru 041 C
CONTROL POWER ENTRY
KNOCKOUTS FOR
POWER ENTRY
LOCATION
((
V,” CONOUI1
\\ -7r5”30
+ 4.60
4
57.50
1-
--F
Table 7.
I I
. , . ..---,
AI-F MW.JEL
027C 10.0 13.0 21.5
032C 10.0 13,0 21.5
037C 10.0 13.0 21.5 5.7
041C 10.0 13.0
A B
6.10
?ONNFCTION I CW!ATIC)N.Q I fY3NNFCTU3N n II llNCH~s)
c
w .. ..-.- . . . . . -= --- . . . . .
I I k ---- -... I
Dimensional Data
is-
c D LIQUID
21.5 5.7
T
1
5.7
5.7
1.75TV? SPACING FOR
DIA. ISOLATOR
1.093
MOUNTING HOLES (4)
“-------- . . . . ---- . . . . . . . .
~8
%
~8
%
nu I wm
aYPAss
11A 1 ya
11A 21A 6.94 86.40
11A
11A 21A
AIR
DISCHARGE
J
ISOLATOR LOCATIONS
SUCTION
21A 6.94 68.40
R T
6.94
6.94 8S.40
\ Ll&jlD
CONN.
88.40
IM 404 I Page 7
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