MUA-SVX01A-EN • Direct-Fired Make-up Air
67
Trouble Shooting
WARNING
Hazardous Service
Procedures!
The maintenance and trouble shooting procedures recommended in this section
of the manual could result in exposure to electrical, mechanical or other
potential safety hazards. Always refer to the safety warnings provided
throughout this manual concerning these procedures. When possible,
disconnect all electrical power including remote disconnects before servicing.
Follow proper lockout/tagout procedures to ensure the power can not be
inadvertently energized. When necessary to work with live electrical
components, have a qualified licensed electrician or other individual who has
been trained in handling live electrical components perform these tasks. Failure
to follow all of the recommended safety warnings provided, could result in death
or serious injury.
Table 14. Trouble shooting guide for flame relays
Problem
Occurs In
Occurs If
1. Safety Shutdown (lockout)
Initiate Period
a. Purge card is not installed or removed.
b. Purge card is bad.
c. Configuration jumpers have been changed (after 200 hours).
d. AC line power errors occurred, see Operation.
e. Four minute INITIATE period has been exceeded.
Standby Period
a. Airflow lockout feature is enabled and the airflow switch does not
close after ten seconds or within the specified purge card timing.
b. Flame signal is detected after 30-seconds.
c. Ignition/pilot valve/intermittent pilot valve terminal is energized.
d. Main valve terminal is energized.
e. Delayed (2nd stage) main valve terminal is energized (RM7895C,
D/EC7895C, RM7896C/D)
f. Internal system fault occurred.
g. Purge card is removed.
h. Purge card is bad.
Prepurge Period
a. Airflow lockout feature is enabled and the airflow switch opens.
b. Ignition/pilot valve terminal is not energized.
c. No flame present at end of PFEP.
d. Main valve terminal is energized.
e. Delayed main valve terminal is energized (RM7895C/D).
f. Internal system fault occurred.
g. Purge card is removed.
h. Purge card is bad.
Pilot Flame Establishing Period (PFEP)
a. Airflow lockout feature is enabled and the airflow switch does not
close after 10-seconds or within the specified purge card timing.
b. Flame signal is detected after 30-seconds.
c. Ignition/pilot valve/intermittent pilot valve terminal is energized.
d. Main valve terminal is energized.
e. Delayed (second stage) main valve terminal is energized
(RM7895C/D, EC7895C, RM7896C/D).
f. Internal system fault occurred.
g. Purge card is removed.
h. Purge card is bad.
Main Flame Establishing Period (MFEP)
-RM7895C/D, EC7895C, RM7896C/D
a. Airflow lockout feature is enabled and the airflow switch opens.
b. Ignition terminal is energized.
c. Ignition/pilot valve terminal is not energized.
d. Main valve terminal is not energized.
e. Delayed main valve terminal is energized.
f. No flame present at end of MFEP.
g. Internal system fault occurred.
h. Purge card is removed.
i. Purge card is bad.
Flame Relays
