A.O. Smith T-D2-OS - Page 13

T-D2-IN / T-D2-OS Service Manual
Ver. 1.00
13
CONFIDENTIAL
Check-
point
Part and Description Color of wires Normal range
H1 Gas proportional valve White - red
1 to 15 VDC
(during operation)
and
20 to 40 Ω
H2 Flow sensor
Red - Black 4 to 5.5 VDC
White - Black
1 to 4 VDC (pulse)
1,080 pulse / min
(more than 18 Hz)
I
Air-fuel ratio rod
Yellow - AFR rod
(Between AFR rod and
the computer board)
More than 0.5 μA
(during operation)
Flame rod
Orange - Flame rod
(Between flame rod and
the computer board)
More than 1 μA
(during operation)
J Flow adjustment valve Red - Black
7 to 16 VDC and
0.09 to 0.2 kΩ
J1 Bypass valve Red - Black
7 to 16 VDC and
0.09 to 0.2 kΩ
K Pump connector port White - Black Less than 1.3 Ω