Data Flow Systems TCU800, Installation And Operation Manual

Page: 38 / 162

28
C h a p t e r 4
Electrical Installation and Wiring Diagrams
The electrical interface to the TCU is broken down into several groups of signals. The wiring of each group is detailed in
the following paragraphs.
These instructions are written specifically for a TCU using the built-in pump control process. Although many of them apply
to custom applications as well, the Applications Engineer will be primarily responsible for defining and implementing the
TCU’s inputs and outputs. In this chapter, functions specific to the pump control process are noted as such.
• Maximum wire size to TCU connectors is 12 AWG.
• Use copper conductors only with a minimum rating of 75C.
• The recommended circuit breaker is 10 Amp maximum.
• When using connectors with screw-type terminals, tighten screw terminals to a maximum 7 in-lb (.79 Nm).
• All AC source power wired to the TCU should be from the same leg of the three-phase system.
• The Power LED does not indicate that AC power has been removed. Even if the TCU’s Power LED is not
lit, you should assume that the TCU is still powered. To remove power, you must turn off the external circuit
breaker.
AC Power
The TCU operates from 120 VAC. Verify the input voltage on the TCU’s connector label before wiring. Three terminals
are provided for wiring power:
• P1-5, AC_PWR (AC power)
• P1-6, AC_NEUT (AC neutral)
• P1-7, TGND (earth ground)
Terminal P1-7 is designated Earth or Safety ground. The TCU’s case is also connected to the TGND terminal. Wire in
accordance with Federal, State, and Local Electrical Codes.
The transformer must provide AC neutral. When wiring to a typical three-phase, 4-wire, 240 V transformer that provides
AC neutral, refer to “Wiring AC Power (typical 240V, 4-wire transformer).” Refer to “Wiring AC Power (typical 480 V,
3-wire transformer)” when connecting to a typical three-phase, 3-wire 480 V transformer with no neutral provided.
Note that these diagrams are for typical installations. If your installation deviates from what is shown here, then refer to the
National Electrical Code® (NEC®) Handbook.