0 ignition system -33, 0 ignition system, 0 controls (cont’d) – Reznor UEAS Unit Installation Manual User Manual

Page 30: 3 safety controls (cont’d)

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9.3.2 Limit Control

All units are equipped with a temperature activated auto reset limit control. The

control is factory set and is non-adjustable. If the setpoint is reached, the limit con-

trol will interrupt the electric supply to the gas valve. This safety device provides

protection in the case of motor failure or lack of airflow due to a restriction at the

inlet or outlet. (For location, see

FIGURE 28, page 37.)

CAUTION: The auto reset limit control will continue to

shut down the heater until the cause is corrected. Never

bypass the limit control; hazardous conditions could

result. See Hazard Intensity Levels, page 2.

9.3.3 Vent Temperature

Limiting Switch

All Model UEAS heaters are equipped with a door switch which prevents the

heater from operating when the service door panel is open. The service panel has

a pliable gasket material that fully seals the door to provide added protection from

building air entering the combustion zone of the heater. (For switch location, see

FIGURE 28, page 37.)

9.3.4 Door Switch

9.3.5 Fan Motor

Overload Protection

The fan motor is equipped with thermal overload protection of the automatic reset

type. Should the motor refuse to run, it may be because of improper current char-

acteristics. Make certain that the correct voltage is available at the motor.

This heater is equipped with a direct spark integrated control module (circuit

board). The module monitors the safety devices and controls the operation of the

fan and venter motors and the gas valve between heat cycles.

10.0 Ignition System

Control Status - Green LED Codes

Steady ON ....... Normal Operation, No call for heat

Fast Flash ........ Normal Operation, Call for heat

1 Flash ............. System Lockout, Failed to detect or sustain

flame

2 Flashes ......... Pressure Switch Did Not Close within 30

Seconds of Venter motor

3 Flashes ......... High Limit or Vent Temperature Limit

Switch Open

4 Flashes ......... Pressure switch is closed before venter

motor is energized

Steady OFF ..... Blown Fuse, No Power, or Defective Board

Flame Status - Yellow LED Codes

Steady ON ....... Flame is sensed

Slow Flash ....... Weak flame (current below 1.0 microamps

±50%)

Fast Flash ........ Undesired Flame (valve open and no call

for heat)

FIGURE 25 – DSI Integrated Control

Module (circuit board)

LED lights are visible through a viewport.

1097-83-218

MODEL 1097-218

LED
Lights

9.0 Controls (cont’d)

9.3 Safety Controls

(cont’d)

This heater is equipped with a temperature activated, manually reset switch to

limit the temperature of the vent gases to below 145°F. The switch is attached to

the side of the combustion air venter housing. If the setpoint is reached, the switch

will interrupt the electric supply to the gas valve. If the vent temperature switch

is activated, identify and correct the cause before resetting the switch. Refer to

the Maintenance Section for information on probable causes and instructions on

resetting the switch.

DANGER

If the manual vent temperature switch activates, identify and correct the cause

before resetting the switch. Never bypass the vent temperature switch; hazardous

conditions could result. See Hazard Intensity Levels, page 2.

Form I-UEAS, Page 30

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