Carrier 19CB - Manual (Page 6)

Check Starter — Before starting the 19CB machine,
open the main disconnect and check starter.
1. Remove contactor arc chutes. Be sure con­
tactors move freely and that shipping string has
been removed. Replaee arc chutes.
2. Check contactors for dirt and rust. Clean
contact magnet surfaces lightly with sandpaper.
Do not sandpaper or file silverplated contacts.
Apply a very thin coat of petroleum jelly to
magnet surfaces and then wipe it off. If starter
has been in a dusty atmosphere, vacuum clean
the cabinet and wipe with hnt-free cloth.
3. Remove fluid cups from magnetic overload
relays. Add dashpot oil to cups per instructions
on relay nameplate. Oil is slripped in small vials
usually attached to starter frame near the
relays. Use only dashpot oil supplied with
starter. Do not substitute. Overload relays are
factory set for 108% of motor full load
amperage. Resetting is not normally required,
nor is it recommended except by a qualified
electrical shop.
4. Check transfer timer for proper setting. On
Star-Delta starter, timers have adjustable range
of 10 seconds to 3 minutes and are factory set
for 1 minute. Auto.-Transformer timers have
adjustable range of 1 to 60 seconds and are
factory set at 30 seconds.
5. With main disconnect open, manually open and
close the main control relay (ICR) to be sure it
operates freely.
Check Operation of Safety Controls — As the
following checks are made, control panel lights
should appear as indicated in the diagrams.
□ OFF ON
1
.
Open main disconnect (all
power off to starter and
controls).
Disconnect
main motor leads in
starter.
2. Provide control circuit
power from separate
115-volt source.
n □ □
ON
STOP
START OIL
PUMP
n □ □ n
POUVER SAFETY LOAD
CIRCUIT RECYCLE
PROGRAM
TIMER
□ □ □
ON
STOP
START OIL
PUMP
■ □ □ n
POWER SAFETY LOAD
CIRCUIT RECYCLE
PROGRAM
TIMER
■ □ n
ON
STOP
START OIL
PUMP
■ ■ ■ n
POWER SAFETY LOAD
CIRCUIT RECYCLE
PROGRAM
TIMER
3. Press ON-STOP button
(light goes on). If
SAFETY CIRCUIT light
does not go on, check
resets on condenser high-
pressure safety, low-refrigerant temperature
safety, bearing and motor Ihgh-temperature
circuit breakers and compressor overloads in
starter. Check 3-amp fuse in control center.
If SAFETY CIRCUIT light goes on but
LOAD RECYCLE light stays off, check the
chilled water recycle switch (auto-reset).
If both lights go on, manually trip and reset
motor and bearing high-temperature circuit
breakers, compressor motor overloads in
starter, and low-refrigerant temperature cutout
to be sure they cut off the safety light.
Tripping the chilled water recycle switch will
cut off the LOAD RECYCLE light only.
4. Press ON-STOP button
(light goes out). Remove
and tag gray striped wire
from
control center
terminal
5. Start chilled water and
condenser water pumps.
Press ON-STOP button
(light goes on).
□ □ □
ON
STOP
START OIL
PUMP
■ □ □ n
POWER SAFETY LOAD
CIRCUIT'RECYCLE
PROGRAM
TIMER
■ □ □
ON
STOP
START OIL
PUMP
■ □ □ n
POWER SAFETY LOAD
CIRCUIT RECYCLE
PROGRAM
TIMER
6. Press OIL PUMP button
for several seconds. Pump
should raise oil pressure
16 - 18 psi above refrig­
erant pressure at machine
shutdown condition. SAFETY CIRCUIT and
LOAD RECYCLE lights should go on.
■ □ ■
ON
STOP
START OIL
PUMP
■ ■ ■ n
POWER SAFETY LOAD
CIRCUIT RECYCLE
PROGRAM
TIMER
ELECTRONIC CONTROL PNEUMATIC CONTROL
Fig. 6 — Control Center Components
7. Release OIL PUMP
button. SAFETY CIR­
CUIT light and LOAD
RECYCLE light should go
out.
■ □ n
ON
STOP
START OIL
PUMP
■ □ □ n
POWER SAFETY LOAD
CIRCUIT RECYCLE
PROGRAM
TIMER