Generator interlock kit: Difference between revisions

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{{Orphan|date=January 2013}}

A '''generator interlock kit''' (or just '''interlock kit''') is a device designed to allow safe powering of a home by a [[engine-generator|portable generator]] during a [[power outage]]. It is a less-expensive alternative to purchasing and installing a dedicated [[transfer switch]]. The kit achieves the same function by adding an external interlock onto an existing breaker panel that allows the main breaker to be turned on ''or'' one designated load breaker to be turned on, but not both at the same time. The interlocked load breaker is repurposed as the "backfeed" breaker, and a generator is connected to it (wired directly or through a power inlet).

Under normal conditions, the main breaker is on, accepting power from the external mains into the panel, and the backfeed breaker is off, isolating the generator. The external mains feeds the panel, but the panel cannot [[backfeeding|backfeed]] the generator. [[Backfeeding]] the generator should never be done, because it serves no purpose and risks damaging the generator.

A '''generator interlock kit''' (or just '''interlock kit''') is a device designed to allow safe [[backfeeding]] of a home through a [[engine-generator|portable generator]] during [[power outage]]s, thereby eliminating illegal and/or unsafe [[engine-generator|generator]] [[backfeeding]] situations that could potentially [[electrocution|electrocute]] [[Lineman (technician)|power linemen]] or destroy the generator.<ref>http://www.nooutage.com/interlock_kits.htm</ref>

In generator mode, the backfeed breaker is on, accepting power from the generator into the panel, and the main breaker is off, isolating the external mains. The generator feeds the home by [[backfeeding]] the panel, but the panel cannot backfeed the external mains. [[Backfeeding]] the external mains is unsafe and illegal, because it can potentially [[electrocution|electrocuting]] [[lineworker]]s, start fires, and overload or damage the generator.<ref>http://www.nooutage.com/interlock_kits.htm</ref>

==Operation==

A generator interlock kit is installed on the front cover of the home's [[distribution board|breaker panel]]. It consists of two sliding [[steel]] or [[plastic]] (depending on the brand) plates held together by three bolts. When moved down, the plate blocks the generator backfeed [[circuit breaker]] and allows the main [[circuit breaker|breaker]] to remain on; when moved up, the generator backfeed [[circuit breaker]] may be turned on, but the main [[circuit breaker]] is blocked and will remain off. The generator backfeed [[circuit breaker]] is connected to a generator inlet installed (preferably) on the outside of the structure. A short cord connects the generator to the house inlet, usually through the use ofa [[Industrialindustrial and multiphase power plugs and sockets|twistlock]] plugs and [[AC power plugs and sockets|socketsplug and socket]].

==Advantages==

*UsingLike a [[transfer switch]], an interlock kit allowslets forthe allgenerator ofenergize athe panel's circuitsand toall beof energized,its circuits (up to the load capacity of the generator); whereasnot usingjust acorded generator [[transfer switch]] only allows a few circuits to be operated.<ref>http://www.interlockkitappliances.com/</ref>

*An interlock kit does not require a separate [[distribution board|panel]] to operate; it can beis installed directly on the home's [[distribution board|breaker panel]]. (provided it has an unused 2-pole breaker slot available).

*InterlockA kitsgenerator eliminateinterlock kit (or a transfer switch), eliminates the need for [[extension cord]]s to power [[Homehome appliance|appliance]]s.<ref>http://www.interlockkit.com/</ref>

==Disadvantages==

*Even though many are tested by an independent lab to a UL standard, they do not carry the UL Listing mark.<ref>http://www.nooutage.com/interlock_kits.htm</ref> Without thata markUL Listing, some local electrical inspectors will not allow the use of these interlock kits.

*Removing the [[distribution board|electrical panel's]] cover could allow the generator backfeed breaker to be turned on while the main is on,<ref>httphttps://forums.mikeholt.com/showthread.php?t=113865&page=2</ref> potentially energizing [[power line]]s or overloading the generator, if the generator is connected.

*In some applications, installing an interlock kit requires drilling holes in the panel cover; once it is installed, it cannot be removed.

*Because the main breaker is shut off, homeowners have no way of knowing when utility power is restored, except by manually turning the generator's breaker off and the main breaker back on.<ref>httphttps://www.electriciantalk.com/f2/see-if-power-restored-interlock-kit-33891/</ref> However there is at least one product<ref>http://www.nooutage.com/thp108.htm</ref> that will produce an audible alert indicating that utility power is restored.

*Installing an interlock kit requiresuses anywheretwo fromor 2 to 3three spaces in the existing [[distribution board|breaker panel]].

==References==

{{reflistReflist}}

==External links==

*[httphttps://www.ul.com/global/eng/pages/ UL] Websitewebsite

*[httphttps://natramelec.com/ National Ram Electronics] Websitewebsite

*[http://www.nooutage.com/ NoOutage] Websitewebsite

*[httphttps://www.geninterlock.com/ GenInterlock Inc] Websitewebsite

*[https://enstorageinc.com/best-inverter-generator-review/ Best Generator Guide]

==See also==

*[[Building Code]]

*[[Engine-generator]]

*[[transferTransfer switch]]

*[[UL (safety organization)]]

*[[Building Code]]

[[Category:Electrical power control]]