Hager SFT240 Changeover Switch

[harrism]

hello guys, hope you’re all well.

We are looking at installing the Hager SFT240 changeover switch to three live aboard boats with an electric hookup and a generator on board.

We were looking for a bit of advice if possible please? (We’ve actually asked several independent sparkies to come aboard, which we get either no response or a big NO )

There are consumer units on the three boats, each has a caravan type / 32A hook up plug to the boat. However, the past few weeks has been awful weather and the electricity kept going off with the storms. We all have on board generators, so we’d like to be able to easily switch between mains electric and on board electric.

The Hager SFT240 din rail changeover switches have arrived, lovely and small instead of big bulky pieces of equipment. The question is the wiring (and I’ve spoken to Hager support who say that there is no tech notes on them )

Would the wiring be the following:

Good afternoon, we have purchased Hager SFT240 as a changeover switch. This will be used on live aboard boats with a mains incoming connection, or if out at sea on a generator. Please can you confirm the correct wiring for these switches. Are we correct in saying:

1: Line to main fuse board
5: Neutral to main fuse board

2: Mains Line in
4: on board generator Line in

6: Mains Neutral in
8: on board generator neutral


Many thanks in advance

 

[baldelectrician]

You will probably need more isolators- the changeover switches also need DP switches on each side

What I mean is
1 DP switch for OFF grid > changeover switch
and
1 DP switch for ON grid > changeover switch

I have a second DB at home and I have a Hager SF363 DP changeover switch

The switch I have has a bottom common point- this works well in my consumer unit as the mains comes out of the bottom and feeds the MCB's as well as the neutral bar

I also have an earth rod when working in Island mode

 

[James]

You will probably need more isolators- the changeover switches also need DP switches on each side

What I mean is
1 DP switch for OFF grid > changeover switch
and
1 DP switch for ON grid > changeover switch

I have a second DB at home and I have a Hager SF363 DP changeover switch

The switch I have has a bottom common point- this works well in my consumer unit as the mains comes out of the bottom and feeds the MCB's as well as the neutral bar

I also have an earth rod when working in Island mode

in this case, is the dp isolator required?

assuming the changeover sw is 3 position i.e. grid-off-gen then the board can be isolated if required.
if the changeover sw needs maintenance then turn off the generator and unplug the shore supply.

or am i missing something??

 

[baldelectrician]

in this case, is the dp isolator required?

assuming the changeover sw is 3 position i.e. grid-off-gen then the board can be isolated if required.
if the changeover sw needs maintenance then turn off the generator and unplug the shore supply.

or am i missing something??

Yes
Can that isolator be locked in the off position?

 

[harrism]

Yes
Can that isolator be locked in the off position?

Hi,

No it cannot be locked but we have two 100A isolators on each side which can - 1 for the hookup and 1 for the generator

Many thanks

 

[baldelectrician]

Hi,

No it’s cannot but we have two 100A isolators on each side - 1 for the hookup and 1 for the generator

Many thanks

There needs to be a DP means of isolation- if there are other isolators that can be locked that would be OK in my opinion.