User guide
TS 870 TRANSFER SWITCH 
PM062 REV 5 08/05/05  5  Thomson Technology 
the supply source be arranged such that the phase of highest potential with respect 
to ground is not connected to the power supply inputs to the controller (A Phase for 
both supplies). Failure to do so will result in equipment damage. 
Per NEC Article 384-3 (f) “The B phase shall be that phase having the higher voltage 
to ground on a 3-phase, 4-wire delta connected systems.” 
3.5.  REMOTE START CONTACT FIELD WIRING 
As a minimum, the remote engine start control field wiring shall conform to the local 
regulatory authority on electrical installations.  Field wiring of a remote start  contact 
from a transfer switch to a control panel should conform to the following guidelines to 
avoid possible controller malfunction and/or damage. 
3.5.1.  Minimum #14 AWG (2.5mm
2
) wire size shall be used for distances up to 100ft 
(30m)
1
). For distances exceeding 100 ft. (30m) consult Thomson Technology 
3.5.2.  Remote start contact wires should be run in a separate conduit. 
3.5.3.  Avoid wiring near AC power cables to prevent pick-up of induced voltages. 
3.5.4.  An  interposing  relay  may  be  required  if  field-wiring  distance  is  excessively 
long (i.e. greater than 100 feet (30m)) and/or if a  remote contact has a 
resistance of greater than 5.0 ohms. 
3.5.5.  The remote start contact must be voltage free (i.e. dry contact).  The use of a 
“powered” contact will damage the transfer controller. 
3.6.  DIELECTRIC TESTING 
Do not perform any high voltage dielectric testing on the transfer switch with the TSC 
80 controller connected into the circuit as serious damage will occur to the controller. 
All AC control fuses and control circuit isolation plugs connected to the TSC 80 must 
be removed if high voltage dielectric testing is performed on the transfer switch. 
3.7.  INSTALLATION OF OPEN TYPE TRANSFER SWITCHES 
Please refer to the factory for additional information. 
4.  GENERAL DESCRIPTION 
Thomson  Technology  TS  870  series  of  Automatic  Transfer  Switches  employ  two  mechanically 
interlocked  enclosed  contact  power  switching  units  and  a  microprocessor  based  controller  to 
automatically  transfer  system  load  to  a  generator  supply  in  the  event  of  a  utility  supply  failure. 










