Raypak VERSA IC, Installation & Operating Instructions Manual

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28. During a heating cycle the flame status, air pres-
sure switch, LWCO, water pressure switch and
other safety switches are continually monitored for
proper state.
29. The System temperature is monitored against the
target temperature to determine the proper firing
rate or staging level. Cascade configuration utilize
sequential staging for follower units as required to
achieve and maintain target temperature.
30. The PIM™ remains in heating mode until the stag-
ing reaches 0% or the firing rate drops below the
configured minimum value for the heater.
31. When the call-for-heat is satisfied the gas
valves(s) are immediately disabled and a blower
post-purge is completed and the controls proceed
to IDLE mode.
32. The pumps complete a purge period as set in the
ADJUST menu.
33. Should a loss of flame occur on Direct Spark
Ignition models during a heating cycle, the control
will energize the high voltage spark igniter within
0.8 seconds for the configured trial-for-ignition
period in an effort to relight the burner (multi-try
models allow 3 tries for ignition with inter-purges).
If the burner relights, normal operation is resumed.
If the burner does not relight, the gas valve is de-
energized immediately and the control will go into
ignition lockout.
34. Should a loss of flame occur on Hot Surface
Ignition models during a heating cycle, the gas
valve is de-energized within 0.8 seconds and the
blower goes through a post-purge. After the flame
recycle delay, the control attempts to relight the
burner (multi-try models allow 3 tries for ignition
with inter-purges). If the burner relights, normal
Fig. 34: PIM™ Connections – DSI Control
Wiring Connections -
PIM™
The following information relates to the wiring connec-
tions on the PIM™, VERSA IC
®
Control and VERSA
IC
®
Display boards. Refer to each product specific
I&O manual for specific connections for specific mod-
els.
operation is resumed. If the burner does not
relight, the gas valve is de-energized immediately
and the control will go into ignition lockout.
NOTE: On CSD-1 controls, recovery from ignition
lockout requires a manual reset by either pushing
the RESET button on the membrane switch (if the
heater is so equipped) or pushing the reset button on
the PIM™ (located next to the LEDs) on lockout con-
trols. Recovery from ignition lockout on auto reset
controls can be accomplished by recycling the call-
for-heat, removing 24VAC (turning the power off to
the heater) from the PIM™ for a minimum of 5 sec-
onds or the control will automatically reset and start
a new heating cycle if the call-for-heat is still active
and the configured reset time has elapsed.