Product Manual A

2. Introduction11-2017

2.5 Specifications

2.5.1 Model OTEC

Transfer Switch Model OTEC Specifications:

Model Amps Cabinet Types Util-to-Gen Gen-to-Gen Util-to-Gen & Util-

to-Util

Transfer

Modes

OTECA 40

125

All Amps:

1, 3R, 4, 4x, 12 X

OTECB 150

225

260

All Amps:

1. 3R, 4, 4x, 12 X

OTECC 300

400

600

All Amps:

1, 3R, 4, 4x, 12 X

OTECD 800

1000

All Amps:

1, 3R, 4, 4x, 12

2.6 Automatic Transfer Switch Typical Function

Automatic transfer switches perform the basic function of transferring the load to the available power

source. The controller monitors each source for allowable voltage and frequency range.

The transfer switch(es) identified on the cover of this manual are designed for each, all or a combination

of the following applications (If you are unsure which of these your transfer switch uses, refer to the

Specifications section of this manual):

2.6.1 Open Transition with Sync Check

Open transition with sync check executes an open transition (OT) transfer when both sources of power

are within specified tolerances of frequency, voltage and relative phase difference. If both sources meet

the tolerances, a fast transfer occurs.

2.6.2 Programmed Transition

Programmed transition executes a programmed transition (PT) transfer by disconnecting the load from the

source of power, pausing in the neutral position of the transfer switch (between switched positions) to

allow transient voltages from the load to diminish, and then the load is switched to the other source.

2.7 Utility-to-Generator Set Operation

In utility-to-generator set applications, the transfer switch performs the following functions:

1. Senses the interruption of the Source 1 power (Utility).

2. Sends a start signal to the generator set (Source 2).

3. Transfers the load to the Source 2 power.

4. Senses the return of Source 1 (Utility).