Carrier 48DH - Manual (Page 8)

Connect wires having insulated probes to each
capacitor terminal. Touch probes to each side of
run capacitor or to compressor motor terminals R
and S. Start compressor; pull probes away after 3
seconds. Discharge start capacitor.
Run compressor for 10 minutes, then shut off
and allow system to equalize (approximately 5
minutes). Try restart without boost capacitor. If
the compressor does not start after 2 attempts
without the boost capacitor, add an accessory start
capacitor relay package per unit wiring diagrams.
^ Start-Up Sequence, Size 002 Natural Gas Units
The following sequences apply to units with
glow coil pilot ignition, indoor (evaporator) fan
motor time delay relay, and Model A643 heat
motor operated gas valve.
MANUAL SEQUENCE
1. With power off, turn gas valve to “On”
position.
2. Set thermostat selector switch at “Heat” posi­
tion and set thermostat dial a few degrees above
room temperature.
3. Turn power on; automatic sequence begins.
AUTOMATIC SEQUENCE
1. Glow coil pilot ignition system and indoor fan
time delay relay energize.
2. Pilot ignites. (If gas pressure is less than 3
in wg, pilot may not ignite, and if air has not
been bled from gas line, pilot will definitely fail
to ignite. Glow coil cycles on for 15 — 20
seconds and off for 1.5 — 2.5 minutes until
conditions are corrected.)
3. Glow coil de-energizes when sensing element of
pilot safety switch is hot enough to indicate a
pilot-proven condition.
4. Main gas valve opens in 1 0 — 1 5 seconds and
main burners ignite.
5. Indoor fan time delay relay closes 30 — 45
seconds after power was turned on; fan motor
starts.
6. Thermostat setting is satisfied and main gas
valve closes in 10 — 14 seconds.
7. Indoor fan motor stops in 1 — 1-1/2 minutes.
^ Start-Up Sequence, Size 003 — 005 Natural Gas
Units
The following sequences apply to units with
spark ignition of pilot, indoor (evaporator) fan
motor time delay relay, and Model A643 heat
motor operated gas valve.
MANUAL SEQUENCE
1. With power off, turn gas valve to “On”
position.
2. Set thermostat selector switch at “Heat”
position and set thermostat dial a few degrees
above room temperature.
3. Turn power on; automatic sequence begins.
AUTOMATIC SEQUENCE
1. Pilot spark ignition system and indoor fan time
delay relay energize.
2. Pilot ignites. (If gas pressure is less than 3
in wg, pilot may not ignite; and if air has not
been bled from gas line, pilot will definitely fail
to ignite. Spark ignition will continue to func­
tion until pilot flame is established. Spark
module electronic circuit will then cut off
spark.)
3. When sensing element of pilot safety switch is
hot enough to indicate a pilot-proven condition
(in 15 — 45 seconds), main gas valve is
energized.
4. Main gas valve opens in 10 — 15 seconds and
main burners ignite.
5. Indoor fan time delay relay closes 30 — 45
seconds after power was turned on; fan motor
starts.
6. Thermostat setting is satisfied and main gas
valve closes in 10 — 14 seconds.
7. Indoor fan motor stops in 1 — 1-1/2 minutes.
Start-Up Sequence, LP Gas Units Without Fan
Purge
The following sequences apply to units with
glow coil pilot ignition, indoor (evaporator) fan
motor time delay relay and Robertshaw Series
7000 BGVE gas valve.
MANUAL SEQUENCE
1. With power off, turn gas valve to “On”
position.
2. Set thermostat selector switch at “Heat” posi­
tion and set thermostat dial a few degrees above
room temperature.
3. Turn power on.
AUTOMATIC SEQUENCE
1. Pilot glow coil and indoor fan time delay relay
energize.
2. Pilot ignites. (If gas pressure is less than 8
in. wg, pilot may not ignite; and if air has not
been bled from gas line, pilot will definitely fail
to ignite Glow coil remains energized until
pilot lights.)
3. Glow coil de-energizes when safety pilot switch
sensing element is hot enougli to indicate a
pilot proven condition.
4. Main gas valve opens; main burners ignite.
5. Indoor fan motor starts in 30 — 45 seconds.
6. Thermostat setting is satisfied; main gas valve
closes.
7. Indoor fan motor stops in I — 1-1/2 minutes.