Powering Your Emerson/Copeland Equipment

Controller Power

Powering your Emerson Controllers, including E2, Site Supervisor, and E3 is easy. Our Class 2 transformer, part number ETC-0040, is all you need to successfully power your controller using any 120v or 208v power source.

Powering the I/O Boards

All models of E2-compatible I/O boards require 24VAC Class 2 input power. Some boards such as the 16AI, 8RO, 4AO, 8DO, MultiFlex ESR, and MultiFlex 16 use a center-tapped power source. All other models, such as the 8IO and MultiFlex Combination I/O boards, may use non-center tapped power sources. BuyEMS.net supplies a wide variety of 24VAC transformers with varying sizes and either with or without center taps. Table 1 shows the transformer sizes and whether they are center-tapped or non-center-tapped. Table 2 lists each board, the board’s rating, and whether or not the board must use center-tapped power.

1-1: Transformers Compatible with I/O Network Boards

1-2: Device power Requirements

To select a power transformer for a board or a series of boards, determine what the total VA is for the boards that will be powered by the transformer. (See table 1-2)

Example: One MultiFlex 8DO (18VA), and two 168AO (15VA each) boards are to be powered by one transformer. The total VA is 48VA. Use a transformer that has a power rating higher than the total calculated VA. Using table 1-1, we are able to determine that a  56VA transformer is sufficient. I/O board transformers should be located within 10 feet of the board it is powering, preferably within the board enclosure.