7800 SERIES EC7885A/RM7885A RELAY MODULE
65-0203
24
17. Run the burner through another sequence, observing
the flame signal for:
a.
Pilot flame alone (unless using direct spark
ignition).
b.
Pilot and main flame together.
c.
Main flame alone (unless monitoring an
intermittent pilot).
Also observe the time it takes to light the main flame. Ignition
of main flame should be smooth.
18. Return the system to normal operation.
19. Make sure all readings are in the required ranges
before proceeding.
NOTE:
After completing these tests, open the master switch
and remove all test jumpers from the subbase
terminals, limits/controls or switches.
Initial Lightoff Check for
Direct Spark Ignition
This check applies to gas and oil burners that do not use a
pilot. It should immediately follow the preliminary inspection.
Refer to the appropriate sample block diagram of field wiring
for the ignition transformer and fuel valve(s) hookup.
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 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
R885A to complete the INITIATE period. Press the Start
Switch to bring on Ignition. When the PILOT LED lights
after the 7885 has completed its Safe-Start Check,
listen for the click of the first stage fuel valve(s) . See
Fig. 17 or 7885A 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; try 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,
release 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.
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 Amplifier
and 1M ohm/volt meter, 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 7885, then press the Start
Switch and the Ignition Transformer will be energized.
After a two-second delay for the 7885 to complete its
Safe-Start Check, PILOT IGNITION should begin.
6. After the pilot is established, turn down the pilot gas
pressure 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 Ignition
Transformer. 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.
