Two electric showers, main fuse overload

[Tangowagon]

I have a client that wants two electric showers with a 60A main fuse.
Obvious risk of blowing the main fuse.
Options
Just say no
Do it but explain that both showers must not be used at the same time (good lucknon that one)
As above but run both showers off one 45/50A breaker such that, if they do run both showers, it's the breaker that trips, not the main fuse.
Tell them one electric & one mixer (preferred option)
Thoughts?

 

[Risteard]

Electrical interlock - e.g. Hager SHN2.

 

[ericmark]

I have two electric showers on a 60 amp fuse with a three story house with two kitchens, so two cookers as well with oil central heating, never blown the main fuse, they were in before we bought the house, so it would seem last owners did not blow fuse either, OK only three of us live here, so using both cookers or both showers at the same time is unlikely to happen very often, but can't see if it did blow it would be replaced with a 60 amp, so it would seem been like this since granny flat built, so well over 10 years.

 

[Taylortwocities]

@Tangowagon
This video details the Garo priority board.... Its the way, given the supply limitation. But only one shower at a time.

If they already have hot water then surely

Tell them one electric & one mixer

has got to be the way forward...

 

[Taylortwocities]

...

 

[ebee]

or you could even build your own system using relays and contactors (note - contactors with change over contacts would be the easiest but probably difficult to source) . Example you could have 15 electric showers on a circuit but render it only possible to use one (or maybe 2) at the same time. Actually todays high tech would often render it far easier to use an app. You are only limited by your own imagination (and the amount of work and money you are prepared to throw at it)

 

[Taylortwocities]

or you could even build your own system using relays and contactors

Yes, but - unless designed properly - you could leave a soapy mother in law standing with no water in shower 1 when your teenage daughter decides to have a 30 minute drenching in shower 2.
Garo, etc, have an interlock system to prevent this little feature...

 

[ebee]

I meant that once a shower was running the relays/contactors would not allow the others to run. That one shower would need to de-energise for any of the others to start. Unless you are envisaging a temporary stop to soap up? Or do some women soap up before commencing the shower?

I, perhaps in error, assumed that most folk do as I do, run shower, get wet, soap up, rinse the stop showerwith maybe at some times after the rinse then another soap and rinse before stopping shower - complete operation from start to finish, men taking circa 10 mins or possibly 20 mins whilst women taking about 17 years or so

 

[ericmark]

I will likely spend no more than 10 minutes in a shower, and I don't tend to get a shower when cooking, it is very unlikely that both showers will overlap by more than a few minutes so not enough time for the 60 amp fuse to blow, OK it may happen, but highly unlikely.

 

[Taylortwocities]

I will likely spend no more than 10 minutes in a shower, and I don't tend to get a shower when cooking, it is very unlikely that both showers will overlap by more than a few minutes so not enough time for the 60 amp fuse to blow, OK it may happen, but highly unlikely.

Yes, but there may be other people in the house. Dont you have servants that do the cooking?
It's Christmas morning, oven on full whack. Saucepan boiling the sprouts has been on full since mid-August, a couple of bar fires, the young couple are having a joint shower (that'll take much more than 10 minutes!)
and then you hop in for your quick wash in shower #2......

 

[ericmark]

One shower in main house, one in the flat under main house, so I have no idea when daughter is using the shower, and vici versa, and was like that when we bought the house, seems unlikely the DNO would have replaced the 60 amp with another 60 amp if it had ruptured, so seems likely it had never ruptured, so seems garage turned into granny flat around 2004, so not ruptured in 19 years seems likely, OK we don't use electric fires, but two kitchens, three bath rooms, etc. So from experience seems unlikely the 60 fuse will rupture.

 

[Murdochcat]

employ a spark ?

 

[flameport]

Tell them one electric & one mixer (preferred option)

Or forget about electric showers completely and have 2x from whatever hot water system they already have.

A 60A fuse is dubious even for 1 electric shower.

 

[SUNRAY]

I meant that once a shower was running the relays/contactors would not allow the others to run. That one shower would need to de-energise for any of the others to start. Unless you are envisaging a temporary stop to soap up? Or do some women soap up before commencing the shower?

I, perhaps in error, assumed that most folk do as I do, run shower, get wet, soap up, rinse the stop showerwith maybe at some times after the rinse then another soap and rinse before stopping shower - complete operation from start to finish, men taking circa 10 mins or possibly 20 mins whilst women taking about 17 years or so

I will likely spend no more than 10 minutes in a shower, and I don't tend to get a shower when cooking, it is very unlikely that both showers will overlap by more than a few minutes so not enough time for the 60 amp fuse to blow, OK it may happen, but highly unlikely.

Oh my goodness what am I doing wrong:

I have a cheap event timer showing how many seconds a contact is closed for. Adding a current switch (clamp) to our shower supply I've been able to accurately show the duration our shower is powered for.

A random few days worth of showers from last year:

I reckon we must be walking around smelly or something as I'm getting 5 or 6 showers compared to only one by others.

 

[Taylortwocities]

Are those figures minutes or hours?