Reznor MAPS - A,B,C Users Manual - Manual (Page 36)

Form O-MAPSIII&IV Cabinets A/B/C, Page 36
7.3.3 Troubleshooting - Modulating Control Module used on Cabinet A, B, and C Gas Heat
Sections
The control that operates the furnace in a MAPS ® III Cabinet A, B, and C has a built-in, self-diagnostic capability. The
control continuously monitors its own operation and the operation of the system. The LED on the control indicates the
current state, warnings, failures, and test modes.
Normal Furnace Operation Display
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, venter motor runs for the specified purge
timings. Purge cycles occur immediately before and after each burner operation.
IGNITION Mode (Ign)
System is initiating burner operation – Ignitor 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)
(Board Self Check)
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.
3 Character LED
Display used to show
deep modulation
board codes for
status, alarm, and
error information.
ID Plug
(unique by
heat section
size)
Deep Modulation (Option AG70) Ignition Board is in
the Control Compartment (See FIGURE 1, page 5.)
IQ Controller Signal
Input Terminals (J4)
Board Status
Voltage Output
to IQ (J7)
Board Power
and Signal (J6)
Control Board
Fuse (3A)
Plug Connec-
tion for Board
Control Points
(J8)
• Ball Valve
Actuator Power,
Drive Voltage,
and Feedback
Signal
• Off Board
Digital Venter
Air Pressure
Switch and Unit
Primary Limit
Switch
On board Air Pressure Sensor for Monitoring Inducer Pressure.
Venter Sensing Tubing is connected from Venter housing to
"LO" pressure input point on air sensing transducer.
Gas Manifold PSI Transducer
Plug 3-wire (red, black, and green)
Wiring Connection (J13)
J9, J10, J3, and J2 are
not currently used.
Flame
Sensor
Spade
Connection
(T8)
Inducer
Motor
Capacitor
Spade
Connection
(AUX-L2 T6 )
Inducer Motor Main Power
Connection Spades
(IND-L2 T3 and IND-L1 T2 )
Main Board Supply Power Input
Spades (L1
T1
and L2
T5
)
7.3 Troubleshooting the Heat Section (cont'd)