Carrier 50MQ - Manual (Page 8)

8. Add charge by slowly opening Chargemaster®
valve. If necessary, reduce charge by bleeding at
liquid line Schrader valve. Check outdoor air
and evaporator temperature during procedure.
If they change, refer back to Chargemaster
Charging Chart for new value.
Correct use of Chargemaster ensures an opti­
mum refrigerant charge will be in system when
conditions and system components are normal.
However, the Chargemaster does not solve or fix
system abnormalities It indicates correct charge
for condition of system. It will not make correc­
tions for dirty filters, slow fans, excessively long or
short suction lines, or other abnormal conditions.
This charging device ensures that a correct relation­
ship exists between outdoor temperature, evap­
orator temperature, and suction line temperature
on a specific system.
Table 5 — 50MQ Chargemaster® Charging Chart
OUTDOOR EVAPORATOR TEMPERATURE (F)*
TEMP 28 30 32 34 36, 38 2ÏÔ 42 44 46 48 50|
(F) Suet on Line Te mperatures
60 42 50 65 72
65 40 48 56 У6
70 36 46 56 У6
75 37 46 55 64
80 40 47 55 62
85 42 -48 54 61
90 44 49 55 60
95 40 45 5 C 55 60
100 44 50 54 59
105 50 54 58
‘Saturated temperature which is the equivalent temperature of
pressure taken at the heat pump suction Schrader fitting.
COMPRESSOR REMOVAL
See Table 6 for compressor information and
Fig 10 for component location.
1. Shut off power to unit. Vent refrigerant to
atmosphere or use refrigerant removal methods
shown in Carrier Standard Service Techniques
Manual, Chapter 1.
2. Remove unit corner access panel. Fig. 1.
3. Remove core from suction and discharge line
Schrader valves.
4. Disconnect compressor wiring at compressor
terminal box. Carefully unsweat suction and
discharge (hot gas) lines at compressor. Do not
stress or move compressor discharge line or it
may break at condenser connection.
CAUTION: Excessive movement of copper
lines at compresksor may cause a break where
lines connect to evaporator or condenser.
5. Remove crankcase heater from compressor
base.
6. Remove compressor hold-down bolts. Lift com­
pressor out.
CAUTION: Aluminum tubing is used in
50MQ unit coils. Do not overiieat or place
excessive strain on tubing or damage may
result.
Table 6 — Compressor Data
MODEL V/PH
PRODUCTION
COMPRESSOR
50MQ022
50MQ027
50MQ032
50MQ037
200/1
MB2423CB
MB2723CB
MB3423CB
MB4023CB
50MQ022
50MQ027
50MQ032
50MQ037
230/1
M52423CB
MD2723CB
MC3423CB
MC4023CB
5ÒMQ032
50MQ037
200-230/3
MF3423CB ~
MF4023CB
OIL
RECHARGE (oz)
44
Filter-Drier — Install a filter-drier in compressor
suction line when refrigerant system is opened for
service as described under Compressor Removal.
Fig. 9 shows suggested position of drier. Check
filter-drier pressure drop at drier service port and
unit suction line Schrader fitting. Ensure pressure
drop does not exceed 2 psi.
CONTROL BOX
4-WAY V a L^:
DISCHARGE LINcl
(HIGH SIDE)IS2!r
SCHRADER FITTING
$
FILTER-DRIER
SERVICE
FILTER-DRIER
(FIELD SUPPLIED)
SUCTION LINE
accumulator ;
SUCTION LINE
(LOW SIDE)"
SCHRADER FITTING
COMPRESSO!
COMPRESSOR HOLD­
DOWN BOLTS (4)
COMPRESSOR ’
TERMINAL BOX
Fig. 9 — Compressor Removal
MAINTENANCE
Lubrication
COMPRESSOR contains factory oil charge. Re­
place oil when lost. See Table 6 for oil recharge. If
necessary, refer to Carrier Standard Service Tech­
niques Manual, Chapter 1, pg 1-21, for oil re­
charging procedure. Use Carrier PP33-1, Texaco
Capella B or Suniso 3G oil.