Power supply safety Q.

[mental4astro (Alexander)]

Hi folks,

I use an inverter to to power an SCT clock drive. It is running of a car battery (not my car's battery). Should I be using one of these plug-in safety switches, or is it ok to use as I've always done?

Mental.

[DavidTrap (David)]

As the inverter isn't connected to ground, the RCD will not detect an electrocution where you connect the active or neutral to ground. However, I believe an inverter is effectively a "floating supply" so if you touch either active or neutral you are OK, but not if you touch both. Happy to stand corrected by anyone with more electrical knowledge than me!

DT

[bojan]

Originally Posted by DavidTrap

As the inverter isn't connected to ground, the RCD will not detect an electrocution where you connect the active or neutral to ground. However, I believe an inverter is effectively a "floating supply" so if you touch either active or neutral you are OK, but not if you touch both. Happy to stand corrected by anyone with more electrical knowledge than me!

DT

Quite correct

[Baddad (Marty)]

David is correct.

And I may Add.
Most electrocutions or shocks happen when the victim touches an active conductor while the body is earthed.

Very few shocks occur between the active and neutral directly. As it requires the victim to touch two conductors.

If you do earth the supply you need to have the earth leakage circuit breaker (safety Breaker). If you do not earth, the safety breaker is not necessary and not operable as David said. The safety breaker does not protect against shocks between active and neutral.

That is about the simplest I can explain it. Hope it helps.

Cheers

[acropolite (Phil)]

Some inverters are grounded or can be grounded allowing RCD operation. (I use a 1200 Watt Selectronic sine wave inverter at my holiday home with an RCD)

Some of the cheaper inverters have one side of the AC output connected to DC ground (non isolated) and can be lethal.

This inverter for example has electrically isolated output, theoretically at least, the neutral side (if not already connected to the earth pin) could be grounded and an RCD used, you would need to firstly ascertain whether your inverter is electrically isolated, then do some tests with an RCD.

If your inverter isn't electrically isolated I wouldn't be using it out in the damp of night.

Google for using an RCD with inverter, you'll find more information.

[mental4astro (Alexander)]

Many thanks for the replies.

I'll do the necessary research and use caution.