Carrier 50MQ - Manual (Page 7)

strainers STRAINERS
Unit Piping
Fig. 8 — 50MQ Refrigerant Flow Diagrams
SERVICE
Table 4 — Service Data
UNIT
R-22 CHG
(Ib-oz)*
Refrig Control
INDOOR FAN
Rpm
Diameter (in.)
Width (in.)
Range Cfm
Motor Hp
OUTDOOR FAN
Cfm
Rpm
Diameter (in.)
Motor Hp
50MQ022 50MQ027 50MQ032 50MQ037
5.0 ) 5 7 5 7
A c c u R a t e r ^
C e n t r i f u g a l — D i r e c t D r i v e
1050-950-850-800
9 9 10
8 8 8
733-915 900-1125 1068-1332
1/4 1/4 1/3
10
8
1230-1540
1/3
P r o p e l l e r — D i r e c t D r i v e
3000
1050
20
1/4
»Factory refrigerant charge.
REFRIGERANT CHARGING
Unit refrigerant system is factory charged.
When recharging is necessary during heating or
cooling season, weigh in total charge indicated in
Table 4. (Charge must be weighed in during heating
season.) Blow any refrigerant remaining in system
before recharging. Standard 1/4-in. Schrader
Service Connections (Fig. 9) are provided on high
and low sides of refrigerant system for evacuation
and charging.
Dial-a-charge charging cylinder is an accurate
device used to recharge systems by weight. These
cylinders are available at refrigeration supply firms.
A Carrier Chargemaster® charging device
(Carrier Part No. 38GC680004) may be used to
check or adjust refrigerant charge
during cooling
season The Chargemaster may also be used as an
alternate method of recharging system.
Chargemaster Operation — Operate unit 10 min­
utes before using Chargemaster.
1. Tape Chargemaster feeler bulb to unit suction
line. Insulate bulb. Ensure suction line is clean
for good contact with bulb.
2. Connect refrigerant drum to Chargemaster inlet
port with drum in position for vapor charging.
3. Connect Chargemaster outlet port (loosely) to
unit suction line Schrader valve.
4. Crack valves on refrigerant drum and Charge-
master to purge lines from drum to suction line
Schrader valve. After purging lines, close valve
on Chargemaster only. Tighten Chargemaster®
connection at suction line Schrader valve.
5. Measure outdoor air dry-bulb temperature at
unit.
6. Read evaporator tem perature at red needle
position on Chargemaster temperature gage and
suction line tem perature at black needle
position
CAUTION: Do not read evaporator tem­
perature with Chargemaster valve open.
7. Enter 50MQ Chargemaster Charging Chart,
Table 5, at outdoor air temperature (step 5)
and evaporator temperature (step 6). Find the
suction line temperature required for correct
system charge. If actual suction line tem­
perature (step 6) is higher than table value, the
system is undercharged. If suction line tem­
perature is lower than table value, the system is
overcharged.
Exam ple- At outdoor air temperature of 85 F
and evaporator temperature of 40 F, the system
will be correctly charged at 48 F (±2 F) suctior
line temperature.