Type S Automatic Load-Transfer Control Installation, Operation, and Maintenance Instructions

INSTALLATION INSTRUCTIONS

A typical automatic transfer scheme is illustrated in Figure 2.

Initial Programming

The control must be programmed with all necessary operating settings prior to operation with energized switchgear. For the desired settings refer to the Operating Instructions section in this manual.

Mounting the Control

Mount the S control in a convenient, accessible location. Maximum distances between the high-voltage transfer switches and potential sensing transformers and the control depends upon the size of the control cable wire and the length of various cable combinations. (See the Interconnecting Cables section in this manual.) Keep in mind that the longer the cable lengths, the greater the susceptibility to surge damage. Therefore, for optimum reliability and economy, locate the switches and transformers as near as possible to the control.

Mounting dimensions are provided in Figure 3.

•For pole-mounted installation, a hole and keyway in the control mounting bracket accommodates a 5/8” bolt.

•For substation installation, the control is factory installed. Leveling is not required.

Grounding the Control

!

WARNING: Hazardous voltage. Solidly ground

all equipment. Failure to comply can result in

 

death, severe personal injury, and equipment damage.

T223.2

The control cabinet must be grounded. A grounding connector on the underside of the cabinet will accommodate No. 14 solid through No. 4 stranded conductors.

For efffective surge protection all control and power conductors for the S control must be routed parallel to a corresponding ground path. For example, the AC power supply for the control should be parallel to and equal in length to the transformer ground path. The control cable should be parallel to and routed close to the switchgear ground path.

Before Placing the Control and Switchgear into Service

!

CAUTION: Equipment misoperation. Do not

energize this equipment until all control settings

 

have been properly programmed and verified. Refer to the Control Programming and Operation section of this manual for programming procedures. Failure to comply can result in misoperation (unintended operation),

equipment damage, and personal injury.

G118.1

Prior to placing the control and switchgear into service, the following installation procedures must be properly completed and verified:

1.Control properly mounted for the installation.

2.Equipment installed according to all locally approved standards and practices.

3.Control and switchgear properly grounded in accor- dance with guidelines in this manual.

4.AC power connected to the control.

5.All control programming entered and verified by appropriate personnel.

Equipment Required

The following equipment is required for a load-transfer installation:

Type S Load-Transfer Control

The control, with or without the fault block accessory, is housed in a cabinet whose outline and mounting dimensions are shown in Figure 3. The control cabinet can be mounted on a pole or substation structure. Leveling is not required. Both the cabinet door and the hinged front panel are equipped with hold-open latches to prevent them from swinging in the open position.

Motor Operated Switches

The three-phase, load break switches require a special wiring accessory for operation with the Type S control. In addition, if fault block is provided, the switches must be equipped with 1000:1 ratio current transformers also available as a factory-installed switch accessory. See the switch installation manual for overall and mounting dimensions and for wiring diagrams.

Potential Transformers

Three-phase voltage sensing is required for control oper- ation. Transformer connections and voltages for various distribution system connections are shown in Figure 5. The voltage sensing relays of the Type S control drop out on a decreasing voltage at 75 volts (min) and pick up on an increasing voltage at 97 volts (max). The control requires 120 Vac, 60 Hz, 500 VA (min) to operate the transformer switches. Quiescent power dissipation at 120 Vac is 18 watts.

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