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Where should I install my transfer switch?

Where you install the transfer switch will depend on the type of switch and what type of generator you will be using. The following installations will work for both manual and automatic transfer switches.

Emergency Distribution:

The transfer switch is installed between a main panel and a sub panel. The main panel connects to the non-essential loads. The sub panel connects to the essential loads. In the event of an outage, the transfer switch will only transfer power to the essential load panel.

This type of installation allows you to purchase a smaller generator and a smaller amperage transfer switch. As a result, it will keep costs down.

Full Load (Non-SE Rated):

The transfer switch will be located after the service disconnect panel of the building. There is the option to manually switch breakers off on any load you do not want to power.

You will want to size your generator and transfer switch amperage to match the load.

Full Load (SE Rated):

An SE rated transfer switch has a service disconnect breaker installed. Therefore, the switch will be installed directly to the utility power entering the building. The main panel will have the essential loads connected. There is the option to manually switch breakers off on any load you do not want to power.

You will want to size your generator and transfer switch amperage to match what will be powered with the generator.

Multiple Services:

One generator can provide backup power to multiple services. You can install the transfer switches in any variation of the three installations mentioned above.

You will want to size the generator large enough to run normal loads and start large motors.

Transfer switch as a Load Control Device:

Starting large motors at the same time will require a large generator to deal with the inrush. A cost effective solution is to install multiple transfer switches. By setting the transfer delay in staggered intervals each load will be added to the generator separately reducing total inrush. You can install the transfer switches in any variation of the three installations mentioned above on each load.

Be sure to size the generator so it will be able to run all connected loads and also have enough amperage to start the last motor.

Do I need a manual or automatic transfer switch?

Manual and automatic transfer switches are an important accessory when it comes to safely switching from utility power to backup power.

How they work

1. Manual transfer switch

When the power fails you need to get your generator set up. Normally you wheel it outside an place it where exhaust fumes cannot seem into windows, doors or vents. Next you need to connect the power cord between the generator and transfer switch. Once you have the generator running you will go to the transfer switch and manually switch from utility to generator power. Once you notice the utility power is back on you reverse the process.

2. Automatic transfer switch

The transfer switch will detect a utility failure and send a signal to the generator to start up. When the generator is at the correct voltage, usually within about 10-30 seconds, the transfer switch will connect power.

As soon as utility power is detected, the switch will signal the generator to shut down, and switch back to the utility power source.

Pros and cons of each system

1. Manual Transfer Switch

Pros –

Your generator is most likely a portable generator and you will be able to move it around.
Cost effective.
You have full control.

Cons –

You have to be present to switch between power sources.
More work.
Requires a little technical skill.
You can run on generator power long after utility power is restored if you aren’t paying attention.

2. Automatic Transfer Switch

Pros –

Easy to use.
You do not have to be on site.
Automatically tests itself.
Less down time between transfer.

Cons –

More expensive.
Generator is permanently mounted.

Matching a transfer switch to a generator

Manual and automatic transfer switches can work with any type of generator. Generally, if you have a portable, towable, or PTO generator, you will select a manual transfer switch. Standby models, such as our PSS or diesel units, you will use an automatic transfer switch. If you have any questions or concerns, give us a call or contact your local electrician.

Why do I need a transfer switch?

Whether you purchased a portable, permanently mounted, or power take-off (PTO) generator you will need to figure out how you will want to get power from the generator to your equipment.

1. Plug equipment directly into the generator.

This is a simple and cost effective way. There are some disadvantages. For example, you will not be able to easily power your furnace or AC; for a light source, you will need lamps. There is also the hazard of the extension cords running through the building. It is also essential that the generator is far enough away from the building to prevent carbon monoxide from getting indoors.

2. Backfeeding

Some people (not us) will recommend backfeeding. Backfeeding is when the flow of electrical energy is in reverse and is injected back into the building without a transfer switch. This is illegal, may be deadly, and should never be attempted – under any circumstances. Backfeeding power into a building has the risk of feeding generator power onto the utility lines. This can cause harm or death to a utility worker when they come to repair a power line . They aren’t expecting power present in the line and you could be criminally prosecuted. Even if you have the main breaker off, this is an illegal practice.

Backfeeding will also cause damage not only to the generator, but everything around it. A huge surge of back-fed power will blow up the generator. This causes a huge fire risk. Take time to read this story submitted by Rick Berry, the Electrical Safety Officer in Vancouver, Canada. https://www.electricgeneratorsdirect.com/stories/13-How-NOT-to-Connect-a-Portable-Generator.html

3. Transfer Switch

The simplest and recommended way is installing a transfer switch.

HOW DOES A TRANSFER SWITCH WORK?

A transfer switch is connected to the utility power, generator power and the building load. Once the power goes out, the switch will disconnect the building from one source of power (utility) then make the connection to the generator. The transfer switch is mechanically interlocked making it impossible to connect the building to both the generator and utility at the same time. This is the same concept for both manual and automatic switches.

What does WINCO provide?

At WINCO, we are experts when it comes to recommending the best transfer switch to suit your needs.

Whether you need a manual transfer switch, an ASCO automatic transfer switch, or if you have questions on how to plug your equipment directly to the generator, we are here to help.