Transfer Switch
Caterpillar Transfer Switches are used in order to provide a continuous source of power for lighting and other critical loads. The transfer switch will transfer power from the normal power source to an emergency power source. The transfer of power will take place when the voltage from the normal source falls below a preset limit.
A microprocessor based controller is used in order to monitor voltage. The microprocessor is used to control the system. The controller is located on the cabinet door. The microprocessor will provide accurate control of the transfer switch.
All Caterpillar Transfer Switches are designed for use on emergency systems or standby systems. The transfer switches are also rated for total system loads.
This manual provides information on the installation, operation, and maintenance of the switch. A manual is supplied with each transfer switch. The manual details the features of the switch. The manual should be kept in a readily accessible location in order to provide complete reference information about the transfer switch.
Controller
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| Illustration 1 | g00827879 |
Controls for the CTS (1) Microprocessor (2) Relay transformer box | |
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| Illustration 2 | g00827983 |
Controls for the CTSD (1) Microprocessor (2) Relay transformer box | |
The MX200 Controller consists of two major assemblies: a microprocessor and a relay transformer box (R/T box). See illustration 1 and illustration 2.
The microprocessor contains the System I/O Interface. The microprocessor also contains the liquid crystal display (LCD), and the keypad.
The System I/O Interface is located on the left hand side of the back of the controller (1). The System I/O Interface has the following accessories:
- The output of the engine start relay
- The outputs of the source relays
- Timer that determines the amount of time before transfer
- Pre-signal contact in either direction
- Input that inhibits the transfer to emergency power
- Input that inhibits the transfer to normal power
- Input for Remote Peak test
- Input to transfer off emergency to dead normal
- The network interface card
The relay transformer box (R/T box) (2) contains the relays that are used in order to energize the transfer mechanism of the transfer switch. The R/T box also contains the transformers that are used to drop the line voltage to a control level for the controller input.
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| Illustration 3 | g00824085 |
The LCD and the keypad are located on the exterior of the door. See illustration 3.
The LCD gives the user accessibility to the following components:
- Light emitting diodes (LED) that indicate the sources that are available
- LED indicators that indicate the position of transfer switch
- A display of the countdown of the timers
- A display of reports of the events that are taking place
- A user interface that is used to set the sensors and the timers
- A user interface that is used to configure the logic