Transformer - A.O. Smith T-D2-OS Service Manual

10-16. Transformer

Unit Part #
Function
Failure events
Effects on the water
heater if transformer fails
Error codes when
transformer fails
Diagnostic
Color/Number of wires
White - Black
From the 120 VAC power supply
#702 Takagi Part #
-To transform input voltage from 120 to 100 VAC.
-Every electrical component of the water heater is designed to only work
with a 100 VAC power supply, therefore, the water heater comes equipped
with this transformer.
1. There is no power coming from the transformer.
2. The voltage from the power supply cannot be converted to 100 VAC.
1. The water heater does not operate due to lack of power from
transformer.
2. A failed transformer can cause electrical damage to other electrical
components within the water heater.
1. Visual inspection: connection/breakage of wires and/or signs of electrical
damage.
2. Check voltages of the transformer: Proper range of values shown below.
White – Black
Brown – Brown
T-D2-IN / T-D2-OS Service Manual
EKH09
N/A
120 VAC / less than 1 Ω
100 VAC / less than 1 Ω
Brown - Brown
To power computer
board and heaters
(100 VAC)
32
CONFIDENTIAL
Ver. 1.00
Checkpoint A1,A2