CB780E/CB784E RELAY MODULES WITH VALVE PROVING
750-234
35
32-00150—03
Run/Test Switch Functions
The Run/Test Switch is located on the top side of the
CB780E/CB784E; see Fig. 40. The Run/Test Switch allows
the burner sequence to be altered as follows:
1.
In Prepurge Drive To High Fire Position, the
Run/Test Switch, when placed in the TEST position,
will hold in PREPURGE with the firing rate motor in
the High Fire position.
2.
In the measured PREPURGE sequence, the
Run/Test Switch, when placed in the TEST position,
will cause the PREPURGE timing to stop. The firing
rate motor will be in the High Fire position.
3.
In Prepurge Drive to Low Fire position, the Run/Test
Switch, when placed in the TEST position, will hold
the burner sequence in PREPURGE with the firing
rate motor in the Low Fire position.
4.
In PFEP, the Run/Test Switch, when placed in the
TEST position, will stop the timer during the first
eight seconds when a ten second PFEP is selected or
during the first three seconds when a four second
PFEP is selected, allowing pilot-turn-down test and
other burner adjustments to be made. This activates
a fifteen second flameout timer that permits pilot
flame adjustment without nuisance safety shut-
downs. The Run/Test Switch will be ignored during
PFEP for the CB780E/CB784E if terminals 8 and 9
or 9 and 21 are jumpered.
5.
During RUN, the Run/Test Switch, when placed in
the TEST position, will drive the firing rate motor to
the Low Fire position.
NOTE:
When CB780E/CB784E is switched to the TEST
mode, it will stop and hold at the next Run/Test
Switch point in the operating sequence.
Make
sure that the Run/Test Switch is in the RUN posi-
tion before leaving the installation
.
CHECKOUT
WARNING
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
more 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.
WARNING
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 CB780E/CB784E or Keyboard
Display Module connector.
3. Make sure that all manual fuel shutoff valve(s)
are closed before starting the initial lightoff
check and the Pilot Turndown tests.
4. Do not place 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 the CB780E/CB784E Sys-
tem Annunciation Diagnostics and
Troubleshooting
Bulletin Number CB-7803.
2. Repeat all required Checkout tests after all adjust-
ments are made. All tests must be satisfied with
the flame detector(s) in its final position.
Equipment Recommended
Voltmeter (one megohm/volt minimum sensitivity) 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.
4.
Initial lightoff check for direct spark ignition of oil—
all burners using DSI.
5.
Pilot turndown test—all installations using a pilot.
6.
Hot refractory hold-in test—all installations using
Infrared (lead sulfide) Flame Detectors.
7.
Hot refractory hold-in test—all installations.
8.
Ignition interference test—all installations using
flame rods.
9.
Ignition spark pickup—all installations using Ultravi-
olet Flame Detectors.
10.
Response to other ultraviolet sources—all installa-
tions using Ultraviolet Flame Detectors.
11.
Flame signal with hot combustion chamber—all
installations.
12.
Safety shutdown tests—all installations.
See Fig. 2 and 3 for the location of component parts, and
Fig. 8 and 9 for wiring subbase specifications for terminal
locations.
