Chapter 4 - Connections
Unit comes standard with
120VAC control. Order 240VAC
control as an option if required.
Digital Solid State Soft Starter 48 - 1250A
4.1 Power Connections
Connect appropriate power lines to the unit input terminals marked L1, L2, L3.
Avoid routing power wires near the control board. Connect the motor leads to the
unit terminals marked T1, T2, T3. Refer to NEC standards for wire length and
sizing. Never interchange input and output connections to the unit. This could
cause excessive voltage in the control logic circuit and may damage the unit.
Never connect power factor correction capacitors on the load side of the
unit. The SCRs will be seriously damaged if capacitors are located on
the load side.
The unit cannot be tested without a motor or other test load connected to the
load side of the unit. It may be necessary to use a load bank to test the unit
without a motor. Note that line voltage will appear across the output terminals if
there is no motor or load connected to the unit. In areas where lightning is a
significant problem, stationary air gap lightning arrestors should be considered
and utilized on the input power source.
Connect the ground cable to the ground terminal as labeled on the unit. Refer to
the National Electrical Code for the proper ground wire sizing and be sure that
the ground connector is connected to earth ground.
4.2 Control Connections
4.2.1 Control Power Connections
Separate 120VAC supply is required (order 240 VAC if required). The control
voltage should be connected to pins 1 and 6 of TB1. This control voltage must be
customer supplied, unless an optional control power transformer has been supplied
with the unit. The terminal block TB1 is located on the main power board.
However, on units rated 150 Amps and above, TB1 us brought out to a duplicate
terminal block on the back panel assembly.
TD Series Unit
TD - Series
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