Reznor MAPS - A,B,C Users Manual - Manual (Page 25)

Form O-MAPSIII&IV Cabinets A/B/C, P/N 257004R8, Page 25
4.2 Heat Section
Controls
4.2.1 General
The heat section controls are in the low voltage compartment. See FIGURE 1, page 5.
4.2.2 Ignition System
for Modulating Gas
Control
FIGURE 14A -
Ignition Control
Module (Deep
Modulation Board)
in the Electrical
Compartment
Normal Furnace Operation (LED 3-Character Display in FIGURE 14A)
LED Display Heat Mode Description
OFF Mode (OFF) System Idle - Control board has power, no faults found, no call for heat.
PURGE Mode
(Pur)
System is purging the heat exchanger – No gas on, no flame, inducer runs for
the specified purge timings. Purge cycles occur immediately before and after
each burner operation.
IGNITION Mode
(Ign)
System is initiating burner operation – Igniter energized, modulating valve
moved to ignition setting, gas on. Maintained for the trial-for-ignition period
and the five second flame stabilization period.
WARM-UP Mode
(HEA)
Period between Ignition and Run – System checks completed before
modulation control begins.
RUN Mode (run) Normal modulating operation.
Ignition Retry (rEt) System has had a failed ignition attempt or has lost flame during burner
operation and is beginning another ignition cycle.
The control has a built-in, self-diagnostic capability. The control continuously monitors
its own operation and the operation of the heat section including direct spark ignition,
safety and modulating valves, and venter motor speed. The 3-digit display on the con-
trol indicates the current system state, warnings, failures, and test modes.
Controller LED Information (displayed on power up)
Display Info (example only) Description
C CAb Furnace series or model name, for example, "C cabinet
series"
400 Heat Section Size
nAt or LP Fuel type
1.01 Software version
The control module is located in the control compartment with an additional board to
control spark that is attached directly to the side of the burner. Do not attempt to disas-
semble either board. However, each heating season check the lead wires for insulation
deterioration and good connections.
If replacement is required, these boards must be replaced with identical parts.
3-Character Display
ID
Plug
IMPORTANT: The control
module is P/N 257246 for
all sizes of MAPS ® III&IV
Cabinet C heat sections
and P/N 258319 on all
MAPS ® III&IV Cabinet
A and B heat sections.
However, the ID plug on
each board is unique for
each size of heat section.
A replacement board will
require either a new ID plug
or reuse of the ID plug from
the board being replaced.
NOTE: Operating and
Lockout Error Codes
displayed on ignition
controller 3-character
display ( FIGURE 14A) are
listed in Troubleshooting
Paragraph 7.3.3.
FIGURE 14B - Spark
Ignition Board,
P/N 257975
Spark Board is attached
to the side of the burner.
CAUTION: Due to high
voltage on the spark wire
and electrode, do not
touch when energized. See
Hazard Levels, page 3.