1-26 750-166
CB780/CB784
STATIC CHECKOUT
TABLE 8—STATIC CHECKOUT.
(Continued)
Test
No.
Test
Jumpers
Volt-
meter Normal Operation
If Operation is Abnormal, Check the
Items Listed Below
WARNING
Make sure all manual fuel shutoff valves are closed.
IMPORTANT: Low fuel pressure limits, if used, could be open. Bypass them with jumpers for the remaining Static
Tests (if required).
1None 4-L2 Line voltage at terminal 4. 1. Master switch.
2. Power connected to the master
switch.
3. Overload protection (fuse, circuit
breaker, etc.) has not opened the
power line.
2 None 6-L2 Line voltage at terminal 6. 1. Limits.
2. Burner controller.
3 None 20-L2 Line voltage at terminal 20. 1. Preignition interlocks.
4 4-5 7-L2 1. Burner motor (fan or blower) starts.
2. Line voltage at terminal 7 within
10 seconds.
1. Burner motor circuit.
a. Manual switch of burner motor.
b. Burner motor power supply,
overload protection, and starter.
c. Burner motor.
2. Running or Lockout Interlocks
(including Airflow Switch).
5 4-10 — Ignition spark (if ignition transformer is
connected to terminal 10).
1. Watch for spark or listen for buzz.
a. Ignition electrodes are clean.
b. Ignition transformer is okay.
6 4-8 — 1. Ignition spark (if ignition transformer is
connected to terminal 8).
2. Automatic pilot valve opens (if con-
nected to terminal 8).
NOTE: Refer to wiring diagram of system
being tested.
1. Watch for spark or listen for buzz.
a. Ignition electrodes are clean.
b. Ignition transformer is okay.
2. Listen for click or feel head of valve
for activation.
a. Actuator if used.
b. Pilot valve.
7 4-21 — Same as test no. 6 for connections to terminal 8.
If using direct spark ignition, check the first
stage fuel valve(s) instead of pilot valve.
Same as test no. 6. If using direct spark
ignition, check the first stage fuel valve(s)
isntead of the pilot valve.
8 4-9 — Automatic main fuel valve(s) open. If using
direct spark ignition with intermittent pilot on
terminal 21, check the optional second stage
fuel valve, if used.
1. Listen for and observe operation of
the main fuel valve(s) and actuator(s).
2. Valve(s) and actuator(s).
9 4-3 — Alarm (if used) turns on. 1. Alarm.
10. 4-5 and
12-13
18-L2 Firing rate motor drives open; zero volts at
terminal 18 after motor starts driving open.
1. Low Fire Start Switch.
2. Firing rate motor and transformer.
11 4-5 and
14-13
18-L2 Firing rate motor drives closed; line voltage at
terminal 18 after motor is in Low Fire position.
1. Low Fire Start switch.
2. Firing rate motor and transformer.
12 4-5 and
12-13
19-L2 Firing rate motor drives open; line voltage at
terminal 19 after motor is in High Fire position.
1. High Fire Purge Switch.
2. Firing rate motor and transformer.
13 4-5 and
14-13
19-L2 Firing rate motor drives closed; zero volts at
terminal 19 after m otor starts driving closed.
1. Low Fire Start Switch.
2. Firing rate motor and transformer.
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