Page 1
Number One
AirConditbning
l\Mer
Division of
Carrier Corporation
Carrier Parkway • Syracuse, N Y 13221
Single-Package Heat Pumps
INSTALLATION
Rigging and Unit Placement — Inspect unit for
transportation damage. File claim with transporta
tion agency. Do not drop unit. Keep unit upright.
Units are designed to be hoisted only. However,
units with optional shipping skids may be moved
with a fork truck. Use spreader bars over unit to
prevent sling or cable damage to unit. Level unit by
using unit frame as reference. Leveling tolerance is
± 1 /16 in. per linear ft in any direction. See Fig. 1 for
additional information. Unit weight is shown in
Table 1.
Roof Curb — Assemble and install accessory roof
curb in accordance with instructions shipped with
accessory. (In areas of prolonged sub-freezing tem
peratures or heavy snowfall, the use of an 18-in.
high roof curb is recommended. This permits proper
drainage during defrost.) Refer to Fig. 2.
Install insulation, cant strips, roofing and flashing
as required. Ductwork can be installed to roof curb
«OTES;
t, A!i BTift (lanets jnust be in piece when rtg8^ns
2. Oo not bandte unit wsdi 'torit iruciis.
3. Use4«ei)}esan«i4"24>y-4Vor "4-by-4V'of ctenenaons
shown.
Fig. 1 — Rigging Details
before unit is set in place. Curb should be level. Unit
leveling tolerance is ±1/16 in. per linear ft in any
direction. This is necessary to permit unit drain to
function properly.
Cut hole(s) in roof to accommodate return and
supply ducts only. Refer to accessory installation
instructions.
Roof Mount — Check building codes for weight
distribution requirements.
Alternate Unit Support Methods — Where the
preferred curb or slab mount cannot be used, sup
port unit with sleepers along unit perimeter using
unit curb-support areas. However, if sleepers cannot
be used, support long sides of unit (dimension “A,”
Fig. 3) by three 4-in. by 4-in. pads, equally spaced.
Units may sag if supported by corners only.
Positioning — Position unit so that drifting snow
does not build up on outdoor coil. Provide clear
ances around and above the unit for airflow, safety,
and service access (Fig. 3).
Do not install unit in an indoor location. Do not
locate unit air inlets near exhaust vents or other
sources of contaminated air.
Although unit is weatherproof, guard against
water from higher runoff and overhangs.
Field-Fabricated Ductwork — Secure all ducts to
building structure. Use flexible duct connectors be
tween unit and ducts as required. Insulate and
weatherproof all external ductwork, joints and all
roof openings with flashing and mastic in accord
ance with applicable codes.
Ducts passing thru unconditioned spaces must be
insulated and covered with a vapor barrier.
Unit Duct Connections — Ductwork openings
are shown in Fig. 3.
Economizer Hood Installation, Fig. 4 — The
economizer mechanism and allelectrical connections
are factory installed and adjusted. The hood assem
bly, outdoor air inlet screens and required hardware
are shipped separately and must be field installed.
NOTE: There is a linkage rod and 3 fasteners (speed
nuts) shipped with the economizer hood assembly.
This rod is not required on 50EQ units.
Install economizer hood(s) as follows:
1. Loosen unit top panel sheet metal screws above
outdoor air inlet opening.
2. Assemble hood top panel, side panels and
support channel.
© Carrier Corporation 1979
Form 50EQ-4SI
Page 2
Table 1 — Physical Data
UNIT MODEL
OPERATING WEIGHT (lb)
Base Unit
Base Unit with Economizer
COMPRESSOR
No. .Model
Oil (3GS or B1) pts (per Compr) 10
REFRIGERANT CHARGE R-22
Sys 1*...Sys 2 (lb)
OUTDOOR AIR FANS
No. ...Hp
Frame (NEMA)
Rpm (1-Phase)
IIMDOOR AIR FANS
Motor
Shaft Diam (in.) — RPM 1750
Motor Frame Size
Motor Pulley Pitch Diam (in.)t
Fan Pulley Pitch Diam (in.)
Fan Speed (rpm)
Fan Shaft Diam (in )
Belt No. ...Size
ELECTRIC HEATERS
Heat Anticipator Setting
Stage 1 ...2
HIGH-PRESSURE SWITCH
Cutout (psig)
Cut-in (psig)
LOW-PRESSURE SWITCH
Cutout (psig) 5+3
Cut-in (psig) 20 ± 5
INDOOR AIR FILTERS (2-in.)
Standard; No. ...Size (in.)
Throwaway; No. ...Size (in.)
AIR INLET SCREENS
Manual Damper; No. ...Size (in.)
Economizer; No. .. Size (in.)
Std
Opt
Std
Opt
Std
Opt
Std, A,B
Opt, A,B
Std
Opt
Std, A,B
Opt, A,B
Std
Opt
50EQ024
3300
3450
2 06D824
20.0...21.3
2 . 1
56T
1050
5
7-1/2
1-1/8
1-3/8
1S4T
213T
6 5 6 0
5 3 5 6
106
8
1073 991
1159 1225
1-3/16
2 3V750
2 3V670
1300
9 25
428
320
6 20x25
6. .16x25
3 20x25
50EQ028
3900
Serviceable, Reciprocating Hermetic
Direct Drive, Propeller
Fixed Speed Centrifugal
4075
2. 06D328
10
R-22
23.5..24.0
2 . 1
56T
1050
7-1/2
10
1-3/8
1-3/8
213T
215T
6 5 60
5 6 60
10 6
8
1073 991
1225 1312
1-3/16
2 3V750
2 3V670
1300
9 25
428
320 ± 20
5 ± 3
20 ± 5
18 16x25
4 20x25
50EQ034
4550
4750
2 06D537
10
—
29.1..29.1
3 1
56T
1050
10
15
1-3/8
1-5/8
215T
254T
6 5 5 6
5 3 5 6
10 6
8
1073 925
1159 1225
1-11/16
2 3V750
4 3V710
1300
9 25
428 .jQ
320
5 + 3
20 + 5
9 20x25
12 16x25
_
5 20x25
*System No 1 is bottom portion of indoor coil
fStandard fan motor supplied with standard fan drive pulleys and belts, optional fan motor supplied with optional
fan drive pulleys and belts Pulley A is installed in unit; pulley B is shipped with unit
3. Insert hood flange between unit top panel flange
and unit. Slots are provided in hood flange to
clear sheet metal screws. Tighten sheet metal
screws.
4. Secure hood side panels to outdoor air opening
flanges using screws provided.
5. Install hood support bracket(s) between U-
channel and support channel.
6. Install screen retainer on support channel using
screws in the slots. Do not tighten.
7. Install outdoor air screens.
8. Push retainers snugly against screens and tighten
screws.
Enthalpy Control — Remove enthalpy control
assembly (Fig. 5) from shipping location on hori
zontal deck in return air filter compartment.
Using 4 no. 10-1 /2 screws from envelope in con
trol assembly junction box, mount the enthalpy con
trol assembly to the inside of economizer hood side
panel nearest condenser section (Fig. 6).
Route the 3 wires, coiled near top cover on the
condenser partition, thru knockout in side plate
(Fig. 6). Using wire connectors from envelope in
junction box, wire enthalpy control assembly as
shown in Fig. 7. Use strain reliefs from envelope in
junction box on side plate and junction box (Fig. 6).
Exhaust Air Hood Installation — The optional
power exhaust package hood assemblies and re
quired sheet metal screws are shipped in compart
ment at right of indoor air fan motor.
Using screws provided, install a hood assembly
over each exhaust air opening as shown in Fig. 3.
Power exhaust applies only to units with econo
mizer. The exhaust fan and motor assembly is
factory wired and adjusted. Refer to Service, Ex
haust Air Fan Adjustment if required.
Return Air Filters — Check to be sure return air
filters of the correct type and size are installed in
unit filter racks. Filter data is shown in Table 1. Do
not operate unit without return air filters.
Page 3
Outdoor Air Inlet Screens — Be sure all outdoor
air inlet screens are in place before operating unit.
Condensate Drains — See Fig. 3 for drain loca
tions. Condensate drain is open to atmosphere and
must be trapped. Install a trapped drain line at con
nection to be used. Trap must be at least 4 in. deep
and made of flexible material or be installed so as
to prevent freeze-up.
Condensate drain pan is fitted with a 1-in. FPT
coupling. Condensate drain line may be routed thru
unit base pan or unit side as shown. A grommet is
shipped taped to this drain. Install this gasket in unit
base pan opening or alternate opening on end of unit
as required.
Field Power Wiring — All units have circuit
breakers for compressors, heaters, fan motors and
control circuits. Each unit is factory wired for
voltage shown on nameplate. The main power ter
minal block is suitable for use with aluminum or
copper wire. See Table 2 for use of aluminum wire
on electric heater terminal blocks.
Install conduit connections in unit base pan or
side panel opening provided as shown in Fig. 3.
On all units route power lines to terminal block in
control box as shown in Fig. 8. On units with electric
heat, route second power supply line thru connector
to terminal block in heater compartment.
Locate field-supplied disconnect(s) within sight of
and directly accessible from the unit. All field wiring
must comply with NEC and local requirements.
Affix crankcase heater sticker to unit disconnect
switch.
Voltage to compressor terminals during com
pressor operation must be within voltage range indi
cated on unit nameplate. Phases must be balanced
within 2%. Contact local power company for
correction of improper voltage or phase imbalance.
See Table 2 as required.
Failure due to operation of unit on improper line
voltage or with excessive phase imbalance con
stitutes abuse and may cause damage to unit
electrical components.
Field Control Wiring — Install a Carrier approved
accessory thermostat assembly according to in
stallation instructions included with the accessory.
Locate thermostat assembly in the conditioned
space where it will sense average temperature.
UNIT
50EQ024
50EQ028 50EQ900011
50EQ034
ROOF CURB
MODEL NO.
50EQ900001
50EQ900021
DIMENSIONS (ft-in.)
A
10- Cfl/4 4-11
12-10-3/4
16- 3-1/8 9- 0
B
6-11
4-4
Fig. 2 — Roof Curb Dimensions
D E F
C
—
—
0-6-1/4
—
0-6-1/4Ì0-5-1/8
0-6-1/4 0-5-7/8
0-6
0-5-1/8
3
NOTES
1 Certified dimension drawings are available on
req uest
2. For details of 12-in high roof curb, refer to 48DD
roof curb installation instructions
3. Two field power supplies are required for 50EQ
units with electric heat
Page 4
st.ecT!îtc
f£ATE=i
ACCESS
PANELS
COMPRESSOR
END
ALTERMATE
CO'iTRCl. A'-SE
^OPEMiNG A-'CDNOmT
3 mo 4^ • K 0
AlTERKATE R1EL&-P0ȣR WiRlNG
ALL. l»f:TS
!NDOORA>!ifAN
AMD «LTEft
ACCESS PA MELS
ACTES-yJATE
DRAÎÎi 2|''iCO-ÎÎ'VPr
COiWi miDE)
OL'TCXÎOR A'RPLO'#
- iMOOOSr AiftELOW
Certt^,«cf dimecswR <lf3w»i>gs avaiîab!« on recjwesi.
DiMENSiONS {ft-'jn.)
UNÎT
50EQ
A \ Î0- 9-13''f6 13- S^1/2
8
C
D
E
F : 0- 9-7/8 0- S-7/S : C- 9-7/8
6
H
J
K j 2- A
L
024
5 7- 2-1Î/16 7- 3-1/8
1 4-10-1/2 4-10-1/2
? 4-11 S-11
I 0-10-1/4
■ > ■ ■■ • ■ — ■■
: 3-1/2" N-PT
; 6- 1-V2 9- 0 ■ 11- 5
028
0-10-1/4
..
4“ NPT
...;2-.:4:.:v:
: 17- 1
: 7- 3-1/8
4-10-1/2
■ 11- 0
: 0-10-1/4
■
1
; 4" MPT
i 2-10
034
Mcrrss.
■J Aiiow 12 ft at>ove ar»t^ S ft on
2, for smaller ciearances. contact
3. Refer to Roof Curb Dmrensions
4, The 50EO034ut«t contains ittree
5. Tfte50EQ034 unit contains tnree
Fig. 3 — Base Unit Dimensions
CPTlOKAi.
ECOfJOMSZER HOOO
f iher access panel encf and 4 ft on
fenjatnfns sfdesof unttforairfiow
attd service clearance.
Carrier.
for details of roof openings.
fans.
exhaiist hoods.
POWER WISE CPQiii«® m
DRAIN :
sl^OiAMit"
'■mPT conn. fNSiOEÏ
EtSCTRK tCAT 0«t,V
€
Page 5
Route thermostat cable or equivalent single leads
of no. 18 AWG colored wire from subbase terminals
thru connectors in unit base pan or side panel (Fig.
3) to low-voltage connections in control box as
shown in Fig. 9. Use no. 16 AWG wire for lengths
exceeding 50 feet. Set heat anticipator settings as
indicated in Table 1.
Refer to accessory remote control panel instruc
tions as required.
Outdoor Air Thermostat — Unit is equipped with
a field adjustable outdoor air thermostat. Thermo
stat is shipped taped to right-hand side of unit
control box. Upon start-up, set the thermostat
“close setpoint” to the building load balance point
and unit capacity. Above the setpoint, the space
thermostat controls 2 stages of compression heat
and electric heat is locked out. Below the setpoint,
one stage of compression heat is available and elec
tric heat is controlled by the second stage of the
space thermostat.
Compressor(s) — Loosen compressor hold-down
bolts until sidewise movement of the washer under
each hold-down bolt head can be easily obtained.
Do not loosen completely as bolts are self-locking
and will maintain their adjustment.
Open the compressor discharge and suction
service valves. Replace and tighten valve caps to
prevent leaks.
Liquid Line Service Valves — Open the liquid line
service valves. Replace caps and tighten to prevent
leaks.
Fig. 4 — Economizer Outdoor Air Inlet
Hood Assembly
START-UP
Cooling
1. Open compressor service valves. Replace valve
caps to prevent leaks. Make sure crankcase
heater has been on for at least 24 hours to
drive out any liquid refrigerant in compressor
crankcase. Check compressor oil level. Oil sight
glass should be about half full.
2. Be sure that liquid line service valve is open.
3. Check that setscrews are tight in fan bearing
locking collar, pulley and fan blades.
4. Check pulley alignment and belt adjustment.
Remove tape on indoor fan pulley.
5. Check that internal power wire terminal screw
connections are tight.
6. On 3-phase units, check for correct fan rotation.
7. Set system selector switch at COOL and fan
switch at AUTO. Adjust thermostat at a setting
below room temperature. Compressor no. 1 will
start on closure of no. 1 contactor. An addi
tional rise in room temperature closes cooling
contactor no. 2 in thermostat, energizing no. 2
contactor, no. 2 compressor will start.
8. Check cooling effect at duct supply outlets.
9. Check unit charge. Refer to Refrigeration
Charge in Service section.
Fig. 5 — Enthalpy Control Assembly
Fig. 6 — Enthalpy Control Assembly
Installation Details
Page 6
10. Reset thermostat at a setting above room tem
perature. Compressor(s) will shut off.
TO SHUT OFF UNIT — Set system selector switch
at OFF position or reset thermostat at a setting
above room temperature.
Do not shut off unit circuit breakers except when
unit is to be serviced. Crankcase heaters are ener
gized only when unit power is on.
Units are equipped with Signal-LOC™ compres
sor protective device. Unit shuts down on trip of any
safety device and indicator light on thermostat
comes on. Check reason for safety device trip. Com
pressor restart is accomplished by manual reset at
room thermostat by moving selector switch to OFF
and then ON.
Heating — To start unit, turn on main power
supply. Refer to Crankcase Heaters.
Set thermostat at HEAT, fan at AUTO, and a
setting above room temperature.
First stage of the heating thermostat energizes
compressor no. 1; the second stage energizes com
pressor no. 2. The electric heater elements are not
energized until the field adjustable outdoor air ther
mostat closes. When this occurs, the first stage of the
thermostat energizes compressor no. 1 and no. 2;
the second stage energizes the electric heater
elements.
Fig. 7 — Enthalpy Control Assembly
Wiring Connections
T8t
o u;
CO Q,
««—I |0|
EQUIP GKO
Fig. 8 — Field Power Wiring Connections
REMOVABLE JUMPER
IrR-M^
[S [b] ^ È É1 È È É 0 oil Qi] LJii
CC C5 O > CD q. 00 CD g
Fig. 9 — Field Control Thermostat Wiring
1^ ^ ^ [c]'-
^ O =i ^ 5 z ^
Check heating effect at duct supply outlets.
Check unit operation. Referto heating operation
chart in service section.
TO SHUT OFF UNIT — Set system selector switch
at OFF or set heating selector lever below room
temperature.
TBEfaaosTATasssMSi-v
Safety Relief — A fusible plug in the accumulator
provides pressure relief under abnormal tempera
ture and pressure conditions.
Defrost Cycle — As frost builds up on the outdoor
coil, the defrost thermostat closes and the unit
operates in a defrost cycle (controlled by the defrost
timer and thermostat). During this cycle the outdoor
air fan shuts off and the unit operates on cooling
cycle for a maximum of 10 minutes. During defrost,
bottom of outdoor coil defrosts first to ensure
proper drainage.
If only compresor no. 1 is operating at beginning
of a deUost cycle, compressor no. 2 is started to
maintain warm air supply to conditioned space.
If both compressors are operating, one is pre
vented from defrosting as the other compressor con
tinues thru the defrost cycle. The electric heaters are
not automatically energized during a defrost cycle.
Automatic Changeover (with Automatic
Changeover Thermostat only) — The unit will
automatically switch from heating mode to cooling
mode when the system selector switch is set at
AUTO, and the temperature of the conditioned
space rises to cooling selector lever setting. When
the temperature of the conditioned space falls to the
heating selector lever setting, the unit will auto
matically change from cooling mode to heating
mode.
The thermostat and unit are so connected that
the cooling and heating systems will not operate
simultaneously.
Economizer Operation — If unit is equipped with
a modulating outdoor air control (economizer), it
should operate as follows:
THERMOSTAT SETTINGS — Set enthalpy con
trol to the desired temperature and relative humidity
which provides cooling with outside air only (no
compressor operation). To determine appropriate
setting of enthalpy control:
1. Determine the maximum combination of relative
humidity and temperature of the supply air con
sidered acceptable for the installation.
t
€
Page 7
2. In Fig. 10, locate the percent humidity on the
left-hand scale and the dry-bulb temperature on
the right-hand scale. Example in Fig. 10 uses 60%
RH and 66 F.
3. Draw a straight line connecting the 2 points.
4. Adjust the enthalpy control dial to the setting
indicated on the control setting scale in Fig. 10.
The control setting for the example conditions
is the B range.
Then set mixed air thermostat in unit filter com
partment to desired temperature of air delivered
to the conditioned space (not less than 50 F or
condensation in unit will result).
HEATING OR COMPRESSOR COOLING
Night Switch Closed — The dampers will assume
and hold the ventilation position whenever indoor
air fan is operating. When indoor air fan shuts off,
the outdoor air damper will close.
Night Switch Open — Outdoor air damper remains
in the closed position. No outdoor air is introduced
into the airstream; unit operation is unaffected.
INTERMEDIATE SEASON (FREE COOLING)
Night Switch Closed (Normal daytime operation) —
If outdoor enthalpy is below enthalpy control
setting, the compressor will remain off when the
room thermostat operates the indoor air fan in the
usual manner. The damper will modulate to main
tain the mixed air thermostat (MAT.) setting. If the
outdoor enthalpy rises above the enthalpy control
setting, the unit operates as described in Heating
or Compressor Cooling paragraph above.
Night Switch Open — Unit operates as described in
Heating or Compressor Cooling paragraph above.
Power Exhaust Operation (if fitted) — When unit
is on economizer mode, the outdoor air damper is
open providing low-cost cooling. The exhaust fan
(runs only during economizer operation) exhausts
return air to the outdoors.
Crankcase Heater — Keeps oil free of refrigerant.
Main power must remain on for heater operation. In
case of extended unit shutdown (more than 24
hours), energize heaters at least 24 hours before
starting compressor.
V
H-
z>
X
>
i 40“
a:
sss
its
SL.
50-
20-z
SO
CONTROL
SETTING
SO
'SO
j-~70 S
ii.
sz
X
<
0:
ut
#
TO-
80-
-SO
Fig. 10 — Nomograph for Determining
Enthalpy Control Setting
7
Page 8
Table 2 — Electrical Data, Units 50EQ024
UNIT MODEL
NOMINAL
VOLTS/PH/HZ
50EQ024400
200/3/60
50EQ024500
230/3/60
50EQ024600
460/3/60
VOLTAGE
RANGE
Min
Max
180
229
207
264
414
528
SEE LEGEND AND NOTES, PAGE 9
COMPR
NO. 1, 2
RLA
49 3
44 4
LRA
170
153
77
OUTDOOR
FAN
MOTORS
FLA*Qty
7 6
(ea)
6 6
(ea)
3 3
(ea)
INDOOR
FAN
MOTOR
Hp
5
5
7 5
5
5
7 5
5
5
7 5
7 5
7 5
7.5
" 5"
5
7 5
5
5
7 5
5
5
7 5
7 5
7 5
5
5
7 5
5
5
7 5
5
5
7 5
7 5
7 5
7 5
FLA
16 2
16 2
25 3
16 2
16 2
25 3
16 2
16 2
25 3
25 3
25 3
25.^
13 2
13 2
22 0
13 2
13 2
22 0
13 2
13 2
22 0
22 0
22 0
22 0
é’e
6 6
11 0
6 6
6 6
11 0
6 6
6 6
11 0
11 0
11 0
11 0
EXHAUST
FAN
MOTOR
fla'
Hp
11 0
11 0
11 0
11 0
11 0
11.0
9 6
9 6
9 6
96
9 6
9.6
48
48
48
48
48
48
HEATERS
FLA
162
199
162
199
162
199
162
199
144
240
144
240
144
240
144
240
69 1
115 1
69 1
115 1
69 1
115 1
69 1
115 1
POWER SUPPLY*_
Circuit Circuit
No. 1 No. 2
MCA
.
150
175
175
150
150
175
175
175
175
175
175
175
130
150
150
130
130
150
150
150
150
150
150
150
MOCP
175
175
175
175
175
175
175
175
175
175
175
27 B
15Ò
150
150
150
150
150
150
150
150
150
150
150
70
85
85
65
65
85
85
85
85
85
85
85
80
80
70
70
80
80
80
80
80
80
80
MCA
205
250
205
250
205
250
205
250
200
310
200
310
200
310
200
310
95
150
95
150
95
150
95
150
MOCP
250
250
250
250
250
250
250
250
200
350
200
350
200
350
200
350
100
150
100
150
100
150
100
150
UNIT MODEL
NOMINAL
VOLTAGE
RANGE
VOLTS/PH/HZ
Min
Max
RLA LRA
50EQ028510
208-230/3/60
50EQ028600
460/3/60
414
528 24 8
SEE LEGEND AND NOTES, PAGE 9
Table 3 — Electrical Data, Units 50EQ028
COMPR
NO. 1, 2
86
OUTDOOR
FAN
MOTORS
Qty
2
FLA
3 3
(ea)
INDOOR
FAN
MOTOR
Hp
7 5 242
7 5
100
7 5
7 5
100
EXHAUST
MOTOR
Hp
FLA
— — —
3
24 2
—
30 8
—
24 2
—
24 2
3 11
30 8
FAN
7 5 24 2 3 11 164-192 175
7 5
100
100
100
10.0
7 5
,30 8
3 11 289-322
24 2
—
30 8
—
30 8
3 11 164-192 175
3 11 289-322 175
30.8
—
11
7 5 11 3 4 8
100 14
7 5 11
7 5 11
100
7 5
7 5
100
100 14
100
100
—
— —
—
14
1133
11 3 4 8 161 1 75
—
14
—
14 3
14 3 48
HEATERS
FLA
11
~ —
__
164-192
—
289-322
—
164-192 175
—
289-322 175
— —
—
4 8
4 8
—
—
48
FLA MCA
175
—
175
175
175
—
175
175
175
_
—
75
75
80
96 75
161 1 75
96
96 80
161 1
96 80
161 1
POWER SUPPLY
Ci
cult
N(
j. 1
MOCP
80
75
80
80
200
200
225
200
225-250 225-250
200
370-420 400-450
225
200
205-250
200
370-420
225
205-250
225
370-420
225
205-250
225
370-420
90
90
100
90
90
100
90
90
100
100
100
100
*
Circuit
No. 2
MCA
___
___ ___
—
___
MOCP
225-250
400-450
225-250
400-450
225-250
400-450
___
___
___
120
250
125
250
120 125
250 250
120 125
250
250
120 125
250
250
___
___
___
___
—
—
t
Page 9
Table 4 — Electrical Data, Units 50EQ034
UNIT MODEL
NOMINAL
VOLTS/PH/HZ
50EQ034500
208-230/3/60
50EQ034600
460/3/60
VOLTAGE
RANGE
Max
Min
187
414
COMPR
NO. 1, 2
RLA LRA Qty FLA
254 71 2
528 32 120 3 3 3
240 3 7 6
OUTDOOR
FAN
MOTOR
INDOOR
FAN
MOTOR
Hp
10 30 8
10 30 8 3 9 6
15 41 4
10 30 8
10 30 8
10 30 8
15
10
10 30.8 3
10 30 8 3 9 6 318-376 230 250
15
15
15
15
15
15
10
10 14 3 4.8
15 20
10 14
10 14
10 14
15
101014
10 14 3 48
15
15
15
15
15
15
EXHAUST
FAN
MOTOR
FLA
Hp
— — —
— — —
—
— — —
— —
41 4
30 833
—
41 4
—
41 4
— —
41 4
41 4
3
41 4
3
41.4
3
___ ___
14
—
— —
— —
—
20 3 48
1433
— —
20
— — —
20
— —
20
20 3 48
20 3 48
20 3
HEATERS
FLA
—
9 6
9 6
9.6
—
— —
9 6
9 6
9.6
— —
—
4 8 48115 1
4 8
FLA
—
199-229
318-376
199-229
—
119-229
318-376 230
199-229 230
—
318-376 230
___
—
115.1 100
—
184
—
184
115 1
184
115 1
—
184
MCA
230 250
230
230
230
230
230
230
230
230
230
230
230
100
100
100
100
100
115
100
100
100
100
100
100
115
115
115
POWER SUPPLY
Circuit
No. 1
MOCP
250
250
250
250
250
250
250
250
250
250
250
250
250
250
110
110
110
110 150
110
110
125
110
110
110
110
110
110
125
125
125 230
MCA
— —
—
— —
255-310
— —
420-475
255-310
—
420-475
255-310
—
420-475
255-310
— —
420-475
—
— —
—
— —
230
—
150
230
150
— —
230
150
— —
»
Circuit
No. 2
MOCP
—
300-350
450-500
300-350
—
450-500
300-350
—
450-500
300-350
450-500
___
—
150
250
—
150
250
150
250
150
250
*Fuse only
Compr —
FLA —
Hp
Kw —
LRA —
Compressor MCA
Full Load Amps MOCP
Nominal Horsepower
Kilowatts RLA
Locked Rotor Amps
— Minimum Circuit Amps
— Maximum Overcurrent
Protection
— Rated Load Amps
SERVICE
Cleaning — Inspect unit interior at the beginning of
each heating and cooling season and during each
season as operating conditions require. Remove unit
side panels as required to expose unit interior.
INDOOR COILS — Clean with a stiff brush,
vacuum cleaner or compressed air.
OUTDOOR COIL — Clean with a stiff brush or
vacuum cleaner. When cleaning with compressed air
or low-pressure water or steam, guard against
damaging compressor wiring and nearby controls.
Condenser fan motors are drip-proof but not
waterproof.
CONDENSER SECTION DRAINS — Check that
these drains are clean and drain freely.
CONDENSATE DRAIN — Check and clean
annually at start of cooling season. In winter, keep
drain and trap dry to protect against freeze-up.
RETURN AIR FILTERS — Clean or replace filters
at start of each heating and cooling season and once
during each season or as often as necessary during
each season depending on operating conditions.
Refer to Table 1 for type and size of filter used. Filter
access panels are shown in Fig. 3. Return air filter
tracks will accept 2 layers of one-in. thick filters if
NOTES: (Tables 2
All outdoor fan motors are single-phase motors
1
2
All heaters are 3-phase assemblies
Main power supply (circuit no 1) on all units is suitable for
3
copper or aluminum or wire
Electric heat power supply (circuit no 2) on 240 amp, 230 v,
114 amp, 460 v units is suitable for copper wire only
3, and 4)
2-in. filters are not available. Do not install bag fil
ters in standard filter tracks. Do not install standard
filters or 2-in. high-efficiency filters in bag filter
tracks.
OUTDOOR AIR INLET SCREENS — Clean
screens with steam or hot water and mild detergent.
Do not use throwaway-type filters in place of
screens. To remove screens, loosen fastening bracket
screws and slide out screens.
Lubrication
COMPRESSORS — Each compressor is charged
with correct amount of oil at the factory. Oil level
should be between bottom and mid level of sight
glass when compressor is warm. Refer to 06D Com
pressor Service Manual if additional information
regarding compressor lubrication system is required.
FAN SHAFT BEARINGS — Charge each grease
fitting with a suitable bearing grease at least once a
year. Do not overlubricate.
FAN MOTOR BEARINGS — No relubrication of
outdoor air fan motors or indoor air fan motors is
necessary for first 2 to 5 years of use depending on
operating conditions. Annually thereafter, open,
clean and repack each bearing with a suitable
bearing grease.
Page 10
Indoor Air Fan Adjustment — Fixed fan speeds
are shown in Table 1; note that second pulley is
shipped with unit. For other fan speeds, select fieldsupplied motor or pulleys from Table 5.
Table 5 — Indoor Air Fan Pulley Data
fiSK OSCIC VEMTUSl
UNIT
50EQ
024
028
034
FAN
RPM
! 325 ! 2
■■ 33T r 2 -
i 107.3 T.2.
i 1093 t 2■
f 1159 f21 .122.5: . .2 •
I 1300 j 2
'■"“sis
; 985
' T067.
j 1088
! 1153
:
■■ Ì30S
: 925 1 2-
1073 I 2 -
i 1093 I 2 -
i 1159 f 2 ; 1226 : 2'
i 1300 ; 2
Shaded values indicate standard or optional pulley com
binations available as shown in Physical Data table All
other combinations are field supplied
MOTOR
PULLEY
No. Grooves - Type - In.
3V-5.6 ! 2 ■
3V - 6.0 f2 -
3V - 6.5 1 2 :
3V - 5.0 i 2 ■
3V - '5.3 [ 2 •
.3V,t5.6 J2.
3y - 6.0 i 2
3V - 5.6
3V.'6,0
3V - 6.5
3V - 50
3V - 5.3
5.6 ■{
3V-:60
3V: - SJS. \ 2-
3V - 6.6 1 2 -
3V - 5 0 r 2
3V - 5.6 I 2 -
3V - 6 0 I 2 ■
J
FAN
PULLEY
3V-10 6 2
3V-m'5T2’3V.- 10..6.T.2 :
3V - 8 0:2-
3V- "8X1 |2-
.3y..-...8..0...{.2.;
3V - 8.0 [2_-
3V -T0.6"'t 2 -
3V-T0.6'{2’3V-10,6 |2-
3V - 8 0 i 2 3V - 8.0 ! 2 •
3V- 60 5 2'-
■3V - 9.0 .2 ■
3V-10.6 Ì 2
3V - 10,6 12 -
3V - 8.0' i 2"
f2"
3V- 8.0" p
3V- 8,0, i 4
3V - 8 0 i '2
BELT
NO - SIZE
3V - 710
SV'^TSO'
3y..-..790.
3V - 670
3r-'670-
.3v -:mo
3V-J10
3V - 710 '
9V-750"
'3V.-.750
3V - 670
3V - 670
3^-670.
3V--7503V-750.
■3V-'670
:3V-710
3Y.Ì 710.
3V - 710
PULLEY REMOVAL — Pulleys are of the fixed
type. To remove, shut off unit power. Loosen fan
motor mounting plate and remove belt. Remove
pulley from shaft.
After reinstalling pulley and belt, check pulley
alignment and belt tension as described below.
PULLEY ALIGNMENT ^ Loosen fan shaft pulley
bushing and slide pulley along shaft. Make angular
adjustment by loosening motor mounting plate and
repositioning it as required.
BELT TENSION — Adjust belt tension by moving
motor back until only a SLIGHT BOW appears in
the belts on the slack side of the drive while running
under full load. Secure motor. Recheck belt tension
after 24 hours of operation, adjust as necessary.
Exhaust Air Fan Adjustment — Adjust belt ten
sion so that 1/8-in. deflection at 5- to 8-lb pressure
between pulley centers can be obtained. To change
tension, loosen motor mounting bolts, reposition
motor and tighten mounting bolts. Tighten locknut
and bolt under motor mounting plate to secure in
fixed position.
Outdoor Air Fan Adjustment (Fig. 11) — Shut off
fan power supply. Remove fan guard and loosen fan
hub setscrews. Adjust fan height using a straight
edge laid across fan venturi. Tighten setscrews. Fill
hub recess with permagum to prevent hub from rust
ing to motor shaft.
'i .
Fig. 11 — Outdoor Air Fan Adjustment
Economizer Adjustment
1. Set enthalpy control at its highest setting. If out
door temperature is above 70 F, perform the
following: Install jumper between enthalpy con
trol terminals 1 and 2 (red and yellow wires).
Remove control relay (CR) from unit econo
mizer control panel.
2. Set system selector switch at COOL and set
cooling temperature selector lever at lowest
setting.
Cooling mode may also be simulated by remov
ing the thermostat wires from terminals Y1 and
Y2 and installing a jumper between terminals R
and Yl.
3. Set mixed air thermostat at its lowest setting.
Outdoor air damper will go to fully open position
(indoor air damper closes).
4. Set mixed air thermostat at its highest setting.
Outdoor air damper will go to fully closed posi
tion (indoor air damper opens).
5. Adjust mechanical linkage if necessary, for
correct positioning (Fig. 12). If enthalpy control
terminals were jumped and plug-in control relay
was removed from unit control box in step 1,
remove jumper and replace plug-in control relay
after positioning dampers. If cooling mode was
simulated as described in step 2, be sure to re
move jumper and reconnect thermostat wires
to Yl and Y2.
DAMPER VENT POSITION SETTING
1. Set fan switch on thermostat assembly at FAN
(continuous fan operation) and close night
switch (if used).
2. Set thermostat system selector switch at OFF.
3. Remove cap from vent adjustment screw on top
of damper motor terminal box cover.
Turn adjustment screw slowly until dampers
assume desired vent position. Do not manually
operate damper motor. Damage to motor will result.
10
Page 11
Connect the pressure gage to the service port on
the suction line. Mount the temperature sensing de
vice on the suction line and insulate it so that out
door ambient temperature does not affect the
reading. Indoor air cfm must be within the normal
operating range of the unit.
TO USE COOLING CHARGING CHART —
Take the outdoor ambient temperature and read the
suction pressure gage. Refer to chart to determine
what the suction temperature should be. If the
suction temperature is high, add refrigerant. If the
suction temperature is low, carefully blow some of
the charge. Recheck the suction pressure as charge
is adjusted. Example; 50EQ024, Fig. 13:
#
Fig. 12 — Economizer Damper Details
POWER FAILURE — Dampers do not have a
spring return. In the event of a loss of power,
dampers remain in position until power is restored.
Do not manually operate damper motor. Damage to
motor will result.
Outdoor Temperature
Suction Pressure............................................. 68 psig
Suction Temperature should be............................50 F
Suction Temperature may vary
If Chargemaster® charging device is used, tem
perature and pressure readings must be accom
plished using charging chart, Fig. 13.
LOW CHARGE HEATING — If the outdoor
ambient temperature is above 45 F, operate unit on
cooling and refer to LOW CHARGE, COOLING.
If outdoor ambient is below 45 F, evacuate system
and weigh in specified amount of refrigerant. (Refer
to Table 1.)
...........................................
..........................
85 F
±2F
Refrigerant Charge — Amount of unit refrigerant
charge is listed on unit nameplate (or refer to Table
1). Refer to Carrier Standard Service Techniques
Manual, Chapter 1, Refrigerants.
Unit panels must be in place when unit is
operating during charging procedure.
NO CHARGE — Use standard evacuating tech
niques. After evacuating system, weigh in the speci
fied amount of refrigerant.
LOW CHARGE — Using charging chart (Fig. 13,
14, or 15) add refrigerant until the conditions of the
chart are met. Note that the charging chart is differ
ent from the one normally used. Chart is based on
charging the units to the correct superheat for the
various operating conditions. An accurate pressure
gage and temperature sensing device are required.
Fig. 13 — Charging Chart — Cooling.
50EQ024
11
Page 12
Fig. 14 — Charging Chart — Cooling,
50EQ028
To check system operation during heating
cycle, use correct Heating Cyele Operation Check
Chart (Fig. 16, 17, or 18). This chart indicates
whether a correct relationship exists between sys
tem operating pressures and indoor and outdoor
entering air temperatures. If pressure and tem
perature lines do not intersect on chart, the system
refrigerant charge may not be correet or other sys
tem abnormalities may exist. Do not use Heating
Cycle Chart to adjust refrigerant charge.
3
3 41
-i 4 10 № 22 27
Э a
SUCTION
SUCTION LINE TEMPERATURE (C)
3 6C
-INE TEMP
ERATURE
7
0 e
(F)
Fig. 15 — Charging Chart — Cooling,
50EQ034
Table 6 — Air Quantity Limits
UNIT MINIMUM CFM
50EQ STANDARD AIR
024
028 8,300
034
NOTES
1 Operation below minimum limits may cause a high
pressure condition when unit is on heating cycle
2 The operation of electric resistance heaters above 47 F
when compressor heat is operational is not recom
mended below minimum cfm's Field-adjustable ther
mostat in unit locks out electric heat
6,800
10,080
MAXIMUM CFM
STANDARD AIR
9,000
12,000
14,000
Fig
0
16 — Heating Cycle Operation Chart
50EQ024
t
Fig. 17 — Heating Cycle Operation Chart —
50EQ028
t
12
Page 13
#
#
#
CHECK VALVE
IDENTIFICATION
A
B
C
D
E
F
10
LOCATION
Outdoor
Coil
Header
Outdoor
Coil
Liquid
Line
Leaving
Coil
Outdoor
Coil
Liquid
Line
Feeding
Capillaries
Indoor
Coil
Liquid
Line
Leaving
Coil
Indoor
Coil
Header
Indoor
Coil
Liquid
Line
Feeding
Capillaries
20
30 40
SUCTION PRESSURE (PS)G)
Fig. 18 — Heating Cycle Operation Chart
50EQ034
Table 7 — Check Valve Functions — 50EQ
COOLING
CYCLE
Closed Open
Open
Closed Open
Closed Open
Open
Open
HEATING
CYCLE
Closed
Closed
Closed
COOLING CYCLE
CHECK VALVE STUCK
Open Closed Open
Lose
Circuiting
in Outdoor
Coil Acts
like Low
Charge
Normal
Lose Slight
Amount of
Capacity
Bypasses
Coil and
Floods
Compressor
Normal Bottom
Normal
50
CHECK VALVE STUCK
Normal Normal
Restricted
Liquid
Line
Normal Normal
Normal
Circuits
of Indoor
Coil
Inactive
Restricted
Indoor
Capillaries
Flooding
Outdoor
Coil and
Compressor
Normal Restricted
Lose Indoor
Coil
Circuiting
Symptom of
Low Charge
Lose
Small
Amount of
Capacity
60
HEATING CYCLE
Closed
Top 3 Circuits
Restricted
Normal
Restricted
Outdoor
Capillaries
Liquid Line
Normal
Normal
13
Page 14
Hot gas from compressor flows thru the 4-way valve and is
directed to the outdoor coil header At the header it is condensed
and subcooled thru converging circuits (4-2-1) Refrigerant
leaves the outdoor coil by way of the check valve to the liquid
line
The refrigerant then flows thru the filter-drier and feeds the
indoor coil by way of capillary tubes on each circuit
Each circuit evaporates the refrigerant and the circuits are
combined in the indoor coil header with some of the circuits
flowing thru the check valve
The refrigerant then flows thru the 4-way valve accumulator
and back to the compressor
Hot gas from compressor flows thru the 4-way valve and is
directed to the indoor coil header At the header it is condensed
and directed thru subcooling circuits and out the indoor coil
check valve to the liquid line
The refrigerant then feeds the outdoor coil by way of a strainer
and then thru capillary tubes on each circuit
NOTE: Refrigeration circuitry for cooling and heating cycle is shown for single system: 50EQ, with 2 individual and independent
refrigeration systems operates in identical fashion
3. Each circuit evaporates the refrigerant and the circuits are
combined in the outdoor header with some of the circuits
flowing thru the check valve
4 The refrigerant then flows thru the 4-way valve, accumulator
and back to the compressor
Fig. 19 — Typical Heat Pump Operation
14
t
Page 15
TROUBLESHOOTING CHART, HEATING CYCLE
Page 16
OD
0
O’
0
7T
CJI
fi)
TROUBLESHOOTING CHART, COOLING CYCLE
0
1
CJI
O
C/)
0
a
CJI
o
m
O
S -a
(a
Oi
<D
fi: (D
^ 3
3 CD
< s
F*
CO
CD
(/)
c
C/)
>
«vl
CO
o
C71 CQ
W 51
8
O
a
-0
m
Loading...