Westinghouse Switch warranty Instruction Leaflet 30-470 E

Instruction Leaflet 30-470 (E)

Page 10

Plant Exerciser (as used in Robonic Transfer Switches)

Ratings — Input voltage 120 volts

Contact rating 20 amps at 120 volts resistive S.P.D.T.

Description

Dial A is divided into a 24 hour day and night scale, and has tabs around the periphery which may be adjusted to operate the micro switch within intervals each 24 hours. Each tab represents a 15 minute interval. Dial B has 7 spokes and advances one position for each revolution of Dial A. Each spoke has provision to add a pin to operate the micro switch. These pins represent days of the week and their function is to prevent operation of the micro switches on selected days.

The micro switch has one normally open and one normally closed contact.

Application in Robonic Transfer Switches

The Plant Exerciser is a Program Time Switch which functions to start and stop the engine-generator set and transfer switch automatically at pre-selected intervals or times. It consists of a synchronous electric motor and a gear assembly to rotate a dial 360° each day for a week (168 hours). On the periphery of the dial there are levers or tabs which can be set to operate a mechanical load switch as the dial rotates. These levers can be selected to operate the switch at specific times of the day daily or specific days of the week. The cycle repeats weekly. The Plant Exerciser may be used in two different ways as an accessory for transfer switches.

1.It may be used to simulate an interruption in the normal source of supply at selected intervals, at least once per week, causing the transfer switch components to function, including start-up of the engine-generator set and transfer of load to the generator supply.

At the end of the interval it will initiate the transfer back to normal supply and shut down the engine-generator.

or

2.It may be used to start an engine-generator set at selected intervals, at least once per week, but without causing the transfer switch to operate and transfer the load to the generator supply. At the end of the interval it will cause the engine-generator to shut down.

Instructions — To operate the engine for an interval once each week, with or without operation of the transfer switch.

1.Extend the tabs of Dial A outwards, except those representing the time of day for the running of the engine or operation of the transfer switch.

2.Determine the day of the week for this testing. Install the six brass pins (called skip pins) in the spokes of Dial B representing the other six days of the week.

3.Turn Dial A counterclockwise until the special tab at 12:00 midnight advances Dial B. Turn Dial B until the present day of the week is opposite the copper arrow. Turn Dial A counterclockwise until the correct time of day (or night) is opposite the arrow on the name plate.

4.If the interval of running the engine is desired more than one day per week but at the same time of day, remove the skip pin from the appropriate spoke of Dial B.

Caution

DO NOT insert skip pins in any spoke when that spoke is pointing toward the copper arrow.