SEAL 1422329 - Caterpillar

This manual has been prepared especially for the purpose of familiarizing personnel with the design, application, installation and operation of the applicable equipment.Read the manual carefully and comply with all instructions. This will help prevent accident or damage to equipment that might be caused by carelessness, improper application, incorrect installation, or improper or unsafe operating procedures.Every effort has been expended to ensure that the information in this manual is both accurate and current. However, the manufacturer reserves the right to change, alter, or otherwise improve his product at any time without prior notice.Why A Transfer Switch Is Needed
Whenever a STANDBY power source is to be used to power electrical loads that are normally powered by a NORMAL power source, installation of a transfer switch is required by electrical code. The transfer switch prevents electrical feedback between the two different power sources.An automatic transfer switch is a device used for the purpose of transferring critical electrical loads from a NORMAL power source to a STANDBY power source. Such transfer occurs automatically when the NORMAL power source has failed or is substantially reduced and the STANDBY source voltage and frequency have reached an acceptable (pre-set) level.Transfer Switch Data Plate
A Data Plate is prominently affixed to the transfer switch enclosure.The Data Plate lists System Frequency, Switch Rated Amps, Switch Rated Volts, Serial Number and Model Number.Use the transfer switch only within the amperage and voltage limits shown on the Data Plate. When ordering parts always include all information from the Data Plate.Transfer Switch Selection
The transfer switch must be properly coordinated with the rest of the electrical distribution system. That is, the switch must be carefully selected on the basis of the voltage, continuous current, frequency, short circuit capabilities, etc., of the distribution system in which it is used.The continuous current rating of the switch should be determined on the basis of both the NORMAL and STANDBY electrical loads being supplied. When coordinating a transfer switch with the rest of the electrical distribution system, the following factors are especially important.1. The transfer switch must be capable of carrying full load currents and must also be able to withstand the thermal and electromagnetic effects of the available short circuit currents.2. Transfer equipment and associated wiring must be provided with suitable protective devices (circuit breakers or fuses). Such over-current protective devices must be properly coordinated to permit them to clear a fault without extensive damage to other circuit components.Under abnormal operating conditions where a fault exists between the transfer switch and load, the switch may be subjected to withstand, closing and interrupting conditions as follows.1. Withstand - With the switch closed to the NORMAL power source, it must be able to withstand the energy let-through of the NORMAL source circuit breaker or fuse while that device interrupts the fault.2. Closing - The transfer switch might "close in" on a fault and would then require a closing rating.3. Interrupting - If NORMAL source voltage has dropped below an acceptable level and STANDBY source power is