Cleaver-Brooks CB780 - Safety Shutdown Tests

750-166 1-33
CB780/CB784
CHECKOUT
SAFETY SHUTDOWN TESTS
(ALL INSTALLATIONS)
Perform these tests at the end of Checkout, after all other
tests have been completed. If used, the external alarm should
turn on. Press the CB780/CB784 reset pushbutton to restart
the system.
1. Opening a Preignition Interlock during STANDBY or
PREPURGE period.
a.*Preignition ILK* fault will be displayed on the
VFD. Fault code 10 or 33 will be displayed to
denote the fault.
b. Safety shutdown will occur.
2. Opening a Lockout Interlock during PREPURGE,
PILOT IGN, MAIN IGN or RUN period.
a.*Lockout ILK* fault will be displayed on the VFD.
Fault code 11 or 12 or 21 or 29 will be displayed to
denote the fault.
b. Safety shutdown will occur.
3. Detection of flame 40 seconds after entry to STAND-
BY, fault code 9. Detection of flame ten seconds into Drive
to Purge Rate or during measured PREPURGE time.
a. Simulate a flame to cause the flame signal voltage
level to be at least 1.25 Vdc for 40 seconds after
entry to STANDBY and also simulate a flame
signal for 10 seconds during PREPURGE.
b.*Flame Detected* fault will be displayed on the
VFD. Fault code 9 or 15 or 18 will be displayed to
denote the fault.
c. Safety shutdown will occur.
4. Failure to ignite pilot.
a. Close pilot and main fuel manual shutoff valve(s).
b. Depress the reset button.
c. Start the system.
d. The automatic pilot valve(s) should be energized
but the pilot cannot ignite.
e.*Pilot Flame Fail* fault will be displayed on the
VFD. Fault code 28 will be displayed four or ten
seconds (depending on the jumper configuration
selection for PFEP) after the pilot valve(s) is
energized to denote the fault.
f. Safety shutdown will occur.
5. Failure to ignite main.
a. Open the manual pilot valve(s); leave the main fuel
manual shutoff valve(s) closed.
b. Depress the reset button.
c. Start the system.
d. The pilot should ignite and the flame signal should
be at least 1.25 Vdc but the main burner cannot light.
e. The flame signal should drop below 1.25 Vdc with-
in 3 seconds after the interrupted pilot goes out.
f. *Main Flame Ign.* fault will be displayed on the
VFD. Fault code 19 will be displayed to denote
the fault.
g. Safety shutdown will occur.
6. Loss of flame during RUN.
a. Open the main fuel manual shutoff valve(s) and open
manual pilot shutoff valve(s).
b. Depress the reset button.
c. Start the system. Start-up should be normal and the
main burner should light normally.
d. After the sequence is in the normal RUN period for
at least ten seconds with the main burner firing,
close the manual main fuel shutoff valve(s) to extin-
guish the main burner flame.
e. The flame signal should drop below 1.25 Vdc within
3 seconds after the main flame goes out.
f. *Main Flame Fail* fault will be displayed on the
VFD. Fault code 17 will be displayed to denote
the fault.
g. Safety shutdown will occur.
7. Opening a Preignition Interlock after the first five
seconds of POSTPURGE.
a.*Preignition ILK* fault will be displayed on the
VFD. Fault code 33 will be displayed to denote
the fault.
b. Safety shutdown will occur.
IMPORTANT:
1. If the CB780/CB784 fails to shut down on any of these
tests, take corrective action; refer to CB780/CB784
Troubleshooting and diagnostics manual and return
to the beginning of all Checkout tests.
2. When all Checkout tests have been completed, reset
all switches to original status.