DIYbanter - View Single Post - Interlock locks to be used in lieu of transfer switch

Mark Rand

On Fri, 11 May 2007 18:02:20 -0000, (Chris Lewis)
wrote:

According to Mark Rand :

Has everybody missed the point that fitting proper interlocks is _precisely_
what Iggy is proposing to do? OK he's not buying a nice idiot homeowner retail
kit from home-generators_R_us. He is engineering a solution that is at least
as foolproof and effective. Good luck to him!

It doesn't appear to have enough poles to be effective - it doesn't
switch both sides of the panel. Secondly, it's probably not
approved for the purpose of switching residential feeds, and there
may well be a reason why it wouldn't be.

To do it right is to do it within the NEC (or CEC) with devices
UL or CSA-approved for the purpose, or be able to find an electrical
engineer who is willing to sign off on it.

It's not a switch, it's an interlock. To be interfaced with the switch to
prevent it closing unless the interlock bar is retracted. It thus becomes
physically impossible to have both switches closed at once, since the switch
must be opened in order to be able to extract the key and the key must be in
the interlock in order to close the switch. Since there is only one key
available, only one switch can be closed at a time... even if they are a mile
apart.

Iggy's solution is far safer than the silly panels with switches linked
together. Specifically, it is fail safe.

Mark Rand
RTFM