TS 840 TRANSFER SWITCH
PM057 REV 8 10/01/25
4
Thomson Technology
3.3.
SYSTEM PHASING-HIGH LEG DELTA SYSTEMS
For systems using high leg delta 240V 3 phase 4 wire systems, connection of supply
conductors must have the correct phasing as shown below.
WARNING
Failure to match correct system
phasing will result in serious damage
to the TSC 80 controller.
208V
B
(Orange)
(High Leg)
C
(Yellow)
A
(Red)
N
(White)
PH A
(UA)
Automatic Transfer
Switch (Utility Supply)
PH B
(UB)
PH C
(UC)
Neural
(N)
120V
120V
240V
240V
Where transfer switches are supplied without power isolation transformers (PT1 &
PT2) for ATS control logic it is essential that the orientation of phase conductors of
