FULTON PDWH1000, Installation, Operation And Maintanance Manual

Page: 31 / 50

DO NOT CHANGE THE PRESSURE
SWITCH SETTINGS.
CAUTION
Should overheating occur or the gas
supply fail to shut off, shut off the
gas supply at a location external to
the water heater.
If The Water Heater
Does Not Start
Check that the temperature control is
set higher than water temperature in the
water heater. Check for tripped circuit
breaker or blown fuse.
Check for possible restrictions (foreign
objects, snow, rags, leaves, etc.) in
either the air supply inlet or the exhaust
outlet on the outside of the building.
Check reset switch. Check for proper
water level in the water heater (low
water cutoff).
If the water heater still does not
operate, follow these instructions to
shut off the gas and call your service
technician.
Turn off all electric power to the water
heater if service is required. Turn gas
cock knob clockwise to “OFF” a quarter
of a turn. (Figure 18, Page 26)
Emergency Shut Down
1. Shut off electric power to the
water heater.
2. Shut off the main gas valve.
Sequence of Operation
INITIATE
The RM7865 enters the five second
INITIATE sequence when the Relay
Module is powered. The RM7865 can
also enter the INITIATE sequence if the
Relay Module verifies voltage
fluctuations of +/-10-15% or frequency
fluctuations of +/-10% during any part of
the operating sequence. The INITIATE
sequence lasts for five seconds unless
the voltage or frequency tolerances are
not met. When the tolerances are not
met, a hold condition will be initiated
and will be displayed on the optional
display module for at least five seconds.
When the tolerances are met, the
INITIATE sequence will restart. If the
condition is not corrected and the hold
condition exists for four minutes, the
RM7865 will lockout.
Causes for hold conditions in the
INITIATE sequence are:
• AC line dropout is detected.
• AC line frequency error caused by
using a 60 Hz device on a 50 Hz line or
vice versa.
• AC line noise that can prevent a
sufficient reading of the line voltage
inputs
• Brownouts caused by a low line
voltage.
The INITIATE sequence will be initiated
if the operating control input is
de-energized during PREPURGE.
STANDBY
The RM7865 is ready to start an
operating sequence when the operating
control input determines a call for heat.
The burner switch, limits, operating
control, inter-locks, critical loads and all
microcomputer monitored circuits must
be in the correct state for the RM7865 to
continue into the PREPURGE
sequence.
NORMAL START-UP
PREPURGE
The RM7865 provides a PREPURGE
timing of 35 seconds with power applied
and the RM7865 operating control
indicating a call for heat.
a. Combustion pressure switch, purge
fan switch ILK, burner switch, limits,
operating control and all microcomputer
monitored circuits must be in the correct
operating state.
b. The fan motor output, terminal 5, is
powered to start the PREPURGE
sequence.
c. The purge fan switch ILK input must
close within three seconds to start the
35 second PRE-PURGE; otherwise,
lockout occurs.
Operation
28-PDWH