23
• Make sure that the flame detector is properly mounted.
(Refer to its instruction manual.)
• Disconnect the loads and flame detector wiring. Measure the insulation resis-
tance across the terminals and panel ground, and make sure that the resistance is
50 M
Ω
or more using an insulation tester or megger of 500 Vdc or more.
• Check that all fuel valves and cocks are closed, and the combustion chamber has
been completely vented.
■
How to measure the flame signal
Handling Precautions
• When using the high-sensitivity model, limit the flame voltage to 4.5 V or
less.
(1) Start the controller, and measure the flame voltage for each burner under vari-
ous conditions (at startup, normal operation, etc.).
(2) When measuring the flame voltage, insert the tester probes into the holes to con-
nect to terminals A and B at the bottom front of the controller as shown below.
(3) Refer to the following table for voltage values:
(4) If the flame signal fluctuates, check the flame detector mounting position and
wiring again.
Chapter 3. ADJUSTMENTS FOR TRIAL OPERATION
POWER
FLAME
START
LEVEL
+
–
Input impedance, 100 k
Ω
or more
0 to 5 Vdc range
Black
Red
Tester
Terminal A
Terminal B
Recommended flame voltage
Checklist
• Make sure that flame monitoring is correct.
Stable 2.0 Vdc or more
• The viewing window of the flame detector
must be free of dirt.
• The monitoring tube must not be blocked
with soot.
