|
| |
KEY to fig. 4-20:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Screw, pan-hd, 10-32 x 5/8
Nut, hex, slflkg, 10-32
Washer, flat, no. 10
Compressor motor relay
Heater relay
Screw, fl-hd, 8-32 x 1/2
Nut, hex, slflkg, 6-32
Washer, flat, no. 6 (.156 ID)
Bracket
Condenser, fan relay
Screw, fl-hd, 6-32 x 1/2
Nut, hex, slflkg, 6-32
Washer, flat, no. 6 (.156 ID)
Washer, flat, no. 6 (.149 ID)
Phase sequence relay
Time delay relay.
Circuit breaker
d. Phase Sequence Relay. To remove the phase
sequence relay from three phase units, refer to
figure 4-20 and remove relay as follows:
(1) Remove four screws (11), nuts (12) and
washers (13).
(2) Remove relay (15) and two each of
washers (13 and 14).
e. Time Delay Relay. To remove the time delay
relay, refer to figure 4-20 and remove relay as
follows :
(1) To remove time delay relay (16) from three
phase units, remove the phase sequence relay then
remove two remaining screws (11), nut (12), and
flat washers (13).
(2) To remove time delay relay (18) from
single phase units, remove four screws (11), nuts
(12), and flat washers (13).
f. Control Circuit Breaker. To remove the control
circuit breaker (17, fig. 4-20), remove circuit
breaker nut from front of junction box and pull
breaker to the rear of the junction box.
4-53. Assembly
a. General. Refer to figure 4-20 and install any
components that were removed. After installation
of components, make all the necessary electrical
connections.
b. Control Circuit Breaker. Install control circuit
breaker (17) through opening in junction box with
locating projection in opening provided. Install
breaker nut.
c. Time Delay Relay. Install time delay relay
(16) on junction box. Secure relay to single phase
junction box with four screws (11), nuts (12), and
washers (13). For three phase junction boxes, omit
the two inner sets of hardware.
d. Phase Sequence Relay. To install the phase
sequence relay on three phase junction box proceed
as follows:
(1) Place a flat washer (14) and flat washer
(13) over outer mounting holes of phase sequence
relay.
(2) Install phase sequence relay (15) on
washers and mounting flange of time delay relay.
Install four screws (11) flat washers (13) and nuts
(12).
e. Condenser Fan Relay. Install condenser fan
relay (10) on bracket (9) and secure relay with
three nuts (7) and flat washers (8). Install bracket
on junction box and install screws (6), nuts (7) and
washers (8).
f. Heater and Compressor Motor Relays. Install
heater relay (5) or compressor motor relay (4) and
secure relay with four screws (1), nuts (2) and flat
washers (3).
4-54. Installation
a. Making any electrical connections that were
disconnected during removal.
b. Carefully install junction box into housing and
install seven screws and lock washers.
c. Refer to paragraph 4-48 and install control
module.
d. Refer to paragraph 4-21 and install top front
cover.
Section XVI.
TRANSFORMER, RECTIFIER, AND PRESSURE SWITCHES
4-55. General
The power transformer rectifier, reduces the power
voltage and converts the alternating current to
direct current to operate the coils and switches in
the control circuit. The transformer is rated at a
secondary voltage of 30 vac with a primary voltage
of 115 vac. The transformer and rectifier are
located below the junction box. The high and low
pressure cutout switches are also located below the
junction box with the reset buttons extending
through the front of the housing. The pressure
cutout switches are connected in the refrigeration
system and are electrically connected in the control
system to the compressor motor relay coil. Extreme
high or low pressure opens the circuit causing the
compressor to stop.
4-56. Transformer
a. Testing. Test transformer as follows:
(1) Refer to paragraph 4-21 and remove
top cover. Refer to paragraph 4-50 and partially
remove junction box.
(2) Disconnect leads and check for continuity
across the primary winding and then across the
secondary winding. If either winding is open.
replace the transformer.
4-33
|
