CB780/CB784 RELAY MODULES
32-00207—01 28
CHECKOUT
Explosion Hazard.
Can cause severe injury, death or property
damage.
Do not allow fuel to accumulate in the combustion
chamber. If fuel is allowed to enter the chamber for
longer than a few seconds without igniting, an
explosive mixture could result. It is recommended
that you limit the trial for pilot to ten seconds, and
limit the attempt to light the main burner to two
seconds from the time the fuel has reached the
burner nozzle. In any case, do not exceed the
nominal lightoff time specified by the equipment
manufacturer; close the manual fuel shutoff
valve(s) if the flame is not burning at the end of the
specified time.
Electrical Shock Hazard and Explosion Hazard.
Can cause severe injury, death or property
damage.
1. Use extreme care while testing the system. Line
voltage is present on most terminal connections
when power is on.
2. Open the master switch before removing or
installing the CB780/CB784 or Keyboard
Display Module connector.
3. Make sure all manual fuel shutoff valve(s) are
closed before starting the initial lightoff check
and the Pilot Turndown tests.
4. Do not put the system in service until you have
satisfactorily completed all applicable tests in
this section and any others required by the
equipment manufacturer.
IMPORTANT:
1. If the system fails to perform properly, note the
fault code, fault message, equipment status, and
sequence time on the display. Refer to the Trouble-
shooting section and CB780/CB784 System
Annunciation Diagnostics and Troubleshooting,
Bulletin Number CB-7803.
2. Repeat ALL required Checkout tests after all
adjustments are made. ALL tests must be satisfied
with the flame detector(s) in its FINAL position.
Equipment Recommended:
1. Volt-ohmmeter (one megohm/volt minimum sensi-
tivity) with:
a. 0-300 Vac capability.
b. 0-6000 ohm capability.
c. 0-10 Vdc capability.
Checkout Summary
1. Preliminary inspection—all installations.
2. Flame signal measurement—all installations.
3. Initial lightoff check for proved pilot—all installations
using a pilot.
13 4-5 and
14-13
19-L2 Firing rate motor drives closed; zero volts at
terminal 19 after motor starts driving closed.
1. Low Fire Start Switch.
2. Firing rate motor and trans-
former.
Explosion Hazard.
Can cause severe injury, death or property damage.
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).
14 15-13 — 1. Raise set point of Series 90 controller—firing
rate motor should drive toward open.
2. Lower set point of Series 90 controller—firing
rate motor should drive toward closed.
1. Series 90 Controller.
2. Firing rate motor and trans-
former.
Final
Equipment Damage Hazard.
Failure to remove test and bypass jumpers can damage equipment or affect operation.
On completing these tests, open the master switch and remove all test jumpers from the subbase
terminals. Also, remove bypass jumpers from the low fuel pressure limits (if used).
Table 8. Static Checkout. (Continued)
Test
No.
Test
Jumpers
Volt-
meter Normal Operation
If Operation is Abnormal, Check the
Items Listed Below
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