A transfer switch are used for safe and convenient operation of diesel generators set for backup power. These transfer switches isolates those circuits using generator power during an outage, and eliminates the risk of back feeding the electrical utility, which can cause injury to utility workers. It also eliminates the need to run extension cords around home or office to operate equipment. A transfer switch allows power to be supplied to the service panel either from the utility or the generator system.
There are four types of transfer switches:
The first one is a manually operated meter connected switches and it is designed for generators supplying 7500 watts or less. These are low cost and simple and inexpensive to install.
Second transfer switch manually operates pre-select panels providing 6 to 10 pre-selected circuits that can be used by thesilent diesel generator for power outages situation.
The third manually operated service rated (100A, 200A or 400A) NEMA-1 (indoor rated) or NEMA-3R (outdoor rated) UL rated panels for either single or three phase applications.
The fourth transfer switch is a automatic operated service rated panels.
The first one is a manually operated meter connected switches and it is designed for generators supplying 7500 watts or less. These are low cost and simple and inexpensive to install.
Second transfer switch manually operates pre-select panels providing 6 to 10 pre-selected circuits that can be used by thesilent diesel generator for power outages situation.
The third manually operated service rated (100A, 200A or 400A) NEMA-1 (indoor rated) or NEMA-3R (outdoor rated) UL rated panels for either single or three phase applications.
The fourth transfer switch is a automatic operated service rated panels.
Applications of transfer switches?
For small portable generator system that have light power requirements the use of the meter connecting transfer switches can be cost effective and simple to use. You will need to check with the utility company to make sure they allow the use of this type of transfer switch. The use of a manually operated pre-select type of panel is also suitable for use with smaller generators. Many of these types of transfer switch will only allow 120v applications.
For small portable generator system that have light power requirements the use of the meter connecting transfer switches can be cost effective and simple to use. You will need to check with the utility company to make sure they allow the use of this type of transfer switch. The use of a manually operated pre-select type of panel is also suitable for use with smaller generators. Many of these types of transfer switch will only allow 120v applications.
Service rated manually operated transfer switches allow you to match the size of the service panel so you can power any circuit in the panel subject to the limits of the generator output. These transfer switches allow you to provide power to any breaker in the panel even though you may not be able to use them all at the same time based on your generator size.
An automatic transfer switch or inverter system that has a autostart function is designed to work with the generator autostart system which is usually a part of the generator controller system. These automatic transfer switches are normally sized to match the service entrance panel amperage size or a special emergency panel created to operate special circuits that are needed during any power outage. The automatic transfer switch operates digitally and also has a motorized breaker system. These automatic transfer switches are activated by a two-wire open or closed low-voltage contact system and is connected to the autostart function on the silent diesel generators controller.
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