cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
Princessbetty
Aspiring Contributor
1,092 Views
Message 1 of 10

G.P.O 250v ac

Hello every one,

does anybody know what this is? And can I remove it from inside my home?

  1. rsz_20200303_105336-1.jpg

 

0 Ratings
Reply
9 REPLIES 9
lnajr02
Recognised Expert
1,075 Views
Message 2 of 10

Re: G.P.O 250v ac

Yes its klaxon salve switch ( ringing converter that will switch a mains bell on and off) normally used in farms and big buildings.
The glass thing at the top is mercury so don't damage this...
0 Ratings
Reply
Keith_Beddoe
Distinguished Sage
Distinguished Sage
1,067 Views
Message 3 of 10

Re: G.P.O 250v ac

@Princessbetty 

I would recommend you take the whole thing intact, to your local re-cycling centre, and let them deal with it. Make sure that you disconnect any mains supply feeding it first.

Those units were also used to power mains sirens for early warning systems. If its marked GPO, then it could have been there since WW2.

 

0 Ratings
Reply
Princessbetty
Aspiring Contributor
1,056 Views
Message 4 of 10

Re: G.P.O 250v act

Thanks for the replies, not sure if its powered but there is a cable that goes into a wall box like a switch plate.  The house was built in 1985 so rules out ww2 

0 Ratings
Reply
Keith_Beddoe
Distinguished Sage
Distinguished Sage
1,047 Views
Message 5 of 10

Re: G.P.O 250v act


@Princessbetty wrote:

Thanks for the replies, not sure if its powered but there is a cable that goes into a wall box like a switch plate.  The house was built in 1985 so rules out ww2 


If there is so sign of a siren outside, then it could simply have been for an external bell, as @lnajr02  has said.

Similar devices were used to power sirens during the 1980s.

0 Ratings
Reply
licquorice
Distinguished Sage
Distinguished Sage
1,046 Views
Message 6 of 10

Re: G.P.O 250v act

As @lnajr02  said, it is for sounding a mains operated bell/klaxon. The incoming ringing current when a call is received operates the relay which in turn tilts the mercury switch which completes the electrical circuit for the bell/klaxon.

0 Ratings
Reply
Princessbetty
Aspiring Contributor
1,034 Views
Message 7 of 10

Re: G.P.O 250v act

Just taken another picture this unit sits under the gpo box, one grey power cable goes into the gpo box and the other cable as been cut

rsz_20200303_105344.jpg

0 Ratings
Reply
licquorice
Distinguished Sage
Distinguished Sage
1,027 Views
Message 8 of 10

Re: G.P.O 250v act

That is device to provide a 50VDC supply to telecoms kit from the mains, probably a loudspeaking telephone No 4.

https://www.britishtelephones.com/lst4.htm

None of the kit is required today.

0 Ratings
Reply
Princessbetty
Aspiring Contributor
984 Views
Message 9 of 10

Re: G.P.O 250v act

Could it be part of a carelink intercom system for the elderly or disabled as there is a lot of retirement bungalows around all built in the mid 80's?

0 Ratings
Reply
licquorice
Distinguished Sage
Distinguished Sage
976 Views
Message 10 of 10

Re: G.P.O 250v act

Doubtful, the mains operated bells were usually outdoor bells that were used in noisy environments such as a haulage yard etc. The loudspeaking phone (if that is what the PSU was for) would probably just have been in an office. In any case it is all redundant kit and can be scrapped. Be careful with the mercury though.

The kit all pre-dates the eighties.

0 Ratings
Reply