Farm Generators: Making Connections the Safe Way

Agdex#:	771
Publication Date:	04/99
Order#:	99-007
Last Reviewed:	04/99
History:	Original Factsheet
Written by:	Steve Clarke - Engineer/OMAFRA; Don Holmes - Agricultural Engineering Consultant/Agviro Engineering; Ron MacDonald/Agviro Engineering

Most people depend on a constant supply of electricity for their livelihoods, especially farmers with cows to milk and livestock to feed. The ice storm that wreaked havoc on eastern Ontario in January 1998 demonstrated the importance of having working emergency back-up systems for when the lights, and everything else, goes out.

As many of the farmers who had to deal with the storm learned, making safe and convenient connections between generators and their electrical systems was not always possible. For some, their farms were not equipped with an approved disconnect switch. Others had no generator plug or a plug that would not fit generator receptacles. This was especially true of those who shared one generator among several farms. Many times, this resulted in unsafe connections being made at the electrical panel with such things as clamps or vice grips.

Many different generator connectors can be found on the farm. Currently, most generator manufacturers are installing "Anderson" connectors on new equipment. (see Figure 1 - Generator Plug and Figure 2 - Generator Receptacle).

Figure 1. Generator Plug

Warning

Sharing generators from farm to farm should only be practiced following verification by an electrician that the wiring is correct, even though the connectors themselves may appear compatible.

Figure 2. Generator Receptacle

Even though the Anderson connector is used most widely, compatibility among connectors may still be a problem. The two main reasons for incompatibility are:

• the way the wiring is formatted on the connectors is not standard; and
• the connectors are being installed in different positions on the generator (e.g. upside-down).

For the most common format for wiring those generators found on the farm today, refer to Figure 3 - Wiring Order Generator Receptacle and to the inset in Figure 4 - Common Generator Hook Up.

Figure 3. Wiring Order Generator Receptacle

Figure 4. Common Generator Hook Up

Improperly wired connectors are an electrical safety hazard for people and animals. Improper voltage can damage electrical equipment.

The Ontario Ministry of Agriculture, Food and Rural Affairs is currently working with the generator industry to standardize connection arrangements. The arrangement that appears to be favored by the industry is shown in Figure 4 Common Generator Hook Up. Standards are expected to be put in place by the fall of 1999.

In the meantime, farmers can ensure safe, effective connections by following some of the standard practices being discussed:

• Using Anderson connectors (2-2 pole S.B. gray) [or equivalent] as shown in Figure 1 and Figure 2

• Using the 175A Anderson connector for generators up to 38 kW

• Using the 350 A Anderson connector for 38kW to 80kW generators

• Fixing the Anderson receptacle in the generator with the 'contacts up' as shown in Figure 2, Generator Receptacle and wired as in Figure 3 and inset in Figure 4, Common Generator Hook Up

• Wiring the generator receptacle as shown in Figure 3 and the inset in Figure 4

• Ensuring the wiring order and configuration for plugs is compatible with standard wiring and configuration for generator receptacles (see Figure 2, Figure 3 and Figure 4)

• Connecting the generator at the central metering/disconnect pole via an attached 20 foot length of flexible cable with the appropriate Anderson Plug connector on the end.

This information has been compiled in consultation with the generator industry, farm organizations, other stakeholders and farm surveys.

Funding for this project has been provided under the Canada-Ontario agreement for the Ice Storm Recovery Assistance Program, Annex A, Assistance for the Agricultural Sector and Rural Communities in Eastern Ontario. This program is jointly funded by the Government of Canada and the Government of Ontario.