Specifications

Part Number STH12 9/10 133
Dual Transformers
*DUAL TRANSFORMERS MUST BE WIRED IN
PHASE*
To determine whether transformers are wired in
phase: With power on, take voltage reading at HOT
wire of each transformer. Reading should be
0VOLTS*. If you read voltage, transformers are out of
phase. The positions of the wires on one transformer
must be switched.
*Black to White = 24V AC +/-10%
Black to Black = 0 V AC