First visual check, H. troubleshooting flowchart - quick reference – ADC AD-200 User Manual

Page 22

Is 24 VAC available

at transformer?

Is 24 VAC present from terminal

THS2 to ground?

Is power available

to primary?

Are thermostat contacts and

limit control contacts closed?

Contacts.

Check continuity of wiring to
determine why voltage does

not exist at THS2.

Is jumper installed

from terminal 5 to

ground?

Install

Jumper.

Replace

Transformer.

Determine why

voltage is not

present.

Open thermostat contacts for 30 seconds.

Close contacts and wait for prepurge (if applicable)

period. Is spark present now?

Turn off supply voltage.

Check high voltage cable.

Is it securely attached to

spark transformer?

Correct

Is condition of high voltage

cable good (not brittle,

burnt, or cracked)?

Replace

Is spark electrode

ceramic cracked

or is electrode
grounded out?

Replace

Johnson Control

module G760/761

Replace electrode

assembly.

System was in lockout.

Observe a complete operating

cycle to determine why

control locked out.

No Yes

h. Troubleshooting Flowchart - Quick Reference...

First Visual Check

No Spark And System Does Not Work