Honeywell 7800 Series Manual page 25

NOTE: Low fuel pressure limits, if used, could be open. If so,
bypass them with jumpers during this check.
1. Open the master switch.
2. Complete the normal checkout of the fuel supply and
equipment as recommended by the equipment manufacturer.
3. Close all manual main fuel shutoff valve(s). Check that
the automatic fuel valve(s) are closed. Make sure fuel is not
entering the combustion chamber.
4. Close the master switch and wait ten seconds for the
RM7885A to complete the INITIATE period. Press the Start
Switch to bring on IGNITION. When the PILOT LED lights
after the RM7885 has completed its Safe-Start Check, listen
for the click of the first stage fuel valve(s) . See Fig. 17 or
RM7885A sequencing.
5. Slowly open the manual fuel shutoff valve(s).
6. Watch for the FLAME LED to help determine when
the first stage burner flame is established. If it is established,
proceed to step 12.
7. If the first stage burner flame is not established within
five seconds, or within the normal lightoff time specified by
the equipment manufacturer, close the manual fuel shutoff
valve(s), release the Start Switch, and open the master switch.
8. Wait about three minutes to allow time to purge the
combustion chamber of any unburned fuel. Then check all
burner adjustments.
9. Close the master switch, wait ten seconds, then press
the Start Switch. When the PILOT LED lights, open the
manual fuel shutoff valve; trying again to lightoff the burner.
The first attempt may have been required to purge the fuel
lines and bring sufficient fuel to the burner.
10. If the first stage burner flame is not established within
five seconds, or within the normal lightoff time specified by
the equipment manufacturer, close the manual fuel shutoff
valve(s), release the Start Switch and open the master switch.
11. If necessary, repeat steps 8, 9 and 10 to establish the
first stage burner flame.
12. When the first stage burner flame is established, re-
lease the Start Switch. Make burner adjustments for flame
stability and input rating. If a second stage is used, proceed to
step 15 .
13. Shut down the system by pressing the Stop Switch.
Make sure the burner flame goes out and make sure all
automatic fuel valves close.
14. If used, remove the bypass jumpers from the low fuel
pressure limit and subbase and proceed to step 16.
15. If a second stage is used, make sure the automatic
second stage fuel valve(s) has opened, and check the lightoff
as follows:
a. Slowly open the manual second stage fuel valve(s)
and check for smooth lightoff.
b. Press the Stop Switch and make sure the automatic
fuel valves close.
c. Press the Start Switch and make sure the first and
second stage burners light within the time specified
by the burner manufacturer.
d. Release the Start Switch to shut off the Ignition
Transformer.
e. Make burner adjustments for flame stability and
input rating.
f. Shut down the system by pressing the Stop Switch.
Make sure the burner flame goes out and make sure
all automatic fuel valve(s) close.
g. If used, remove the bypass jumpers from the low
fuel pressure limit and subbase.
16. Press the Start Switch to restart the system. Observe
that the burner operation is established within the normal
lightoff time specified by the equipment manufacturer. Re-
lease the Start Switch to shut off the Ignition Transformer.
17. Check for the proper signal, see Table 5, into the RUN
period. Any pulsating or unsteady readings will require
further attention.
18. Make sure all readings are in the required ranges before
returning the system to normal operation.
PILOT TURNDOWN TEST (ALL INSTALLATIONS
USING A PILOT)
Perform this check on all installations that use a pilot. The
purpose of this test is to verify that the main burner can be lit
by the smallest pilot flame that will hold in the flame amplifier
and energize the FLAME LED. Clean the flame detector(s)
to make sure that it will detect the smallest acceptable pilot
flame. If using AMPLI-CHECK™ or Self-Checking Ampli-
fier and 20 kohm/voltmeter, the flame signal will fluctuate
every time the amplifier does a self-check or a shutter check.
NOTE: These steps may require two people, one to open the
manual valve(s) and one to watch for ignition.
NOTE: Low fuel pressure limits, if used, could be open. If so,
bypass them with jumpers during this test.
1. Open the master switch.
2. Close the manual main fuel shutoff valve(s).
3. Connect a manometer (or pressure gauge) to measure
pilot gas pressure during the turndown test.
4. Open the manual pilot shutoff valve(s).
5. Close the master switch, allow ten seconds for the
INITIATE period of the RM7885, then press the Start Switch
and the Ignition Transformer will be energized. After a two-
second delay for the RM7885 to complete its Safe-Start
Check, PILOT IGNITION should begin.
6. After the pilot has been established, turn the pilot gas
pressure down very slowly, reading the manometer (or
gauge) as the pressure drops. Stop immediately when the
FLAME LED goes out. Note the pressure at this point.
7. Slowly increase the pilot pressure until the FLAME
LED comes on, and then turn it down slowly to obtain a
pressure reading just above the dropout point.
8. Release the Start Switch to shut off the Ingition Trans-
former. Make sure that the automatic main fuel valve(s) is
open. Smoothly open the manual main fuel shutoff valve(s)
and watch for main burner lightoff.
9. If the main flame is not established within five seconds
or the normal lightoff period specified by the burner manu-
facturer, close the manual main fuel shutoff valve(s) and open
the master switch. If the burner flame is established in the
normal lightoff period, proceed to step 11.
25
RM7885A
CHECKOUT
65-0107