4-2
• Disconnect the loads and flame detector wiring. Measure the insulation
resistance across the terminals and panel ground, and make sure that the
resistance is 50M
Ω
or more using an insulation tester or megger of 500Vdc or
more.
• Valves and cocks on each of the fuel lines must be closed, and the fuel
chamber must be thoroughly purged.
■
How to measure the flame signal
Handling Precautions
• When the high-sensitivity model is used, limit the flame voltage to 4.5V.
(1) Start the controller, and measure the flame voltage for each burner under
various conditions (at startup, normal operation, etc.).
(2) When measuring the flame voltage, insert the tester probes into the holes to
connect 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 4. ADJUSTMENTS FOR TRIAL OPERATION
+
–
Input impedance, 100k
Ω
or more
0 to 5Vdc range
Black
Red
Tester
Terminal A
Terminal B
POWER
FLAME
FRS100 FLAME RELAY
Recommended flame voltage
Checklist
• Make sure that flame monitoring is correct.
• The front of the flame detector must be free
of dirt.
• The monitoring tube must not be blocked
with soot.
2Vdc min.
