Electronic Flush Toilets, Sensor with no batt

[Npstewart]

Hi everyone. Im working on a larger health care facility. They are using all electronic sinks and toilets (ie the sensor kind, no battery). I thought it would be a good idea to feed them with the GFI receptacle circuit in the same restroom. Does that sound right? Also, how much load do these things use, I wasn't really going to account for much I mean how many people flush the toilet and wash their hands at any given time?

Do I need to show a xfrmr for these things? Are these typically low voltage?

I think I could load up the mens room circuit with more devices because I saw a statistic one time that most men dont wash their hands.

Thanks for your help everyone

 

[iwire]

Yes they use a transformer they do not draw much at all and no I would not bother to GFCI protect the transformer as that will do nothing about the transformers secondary side.

 

[Npstewart]

Where does the transformer go, under the sink?

I was also thinking about feeding them from the gfi because its the only power I have in the restroom other then the lights.

I saw that most transformers will accept 10 sensors so ill go with that and then count it for like 150 watts if it comes down to it.

 

[charlie b]

My design drawings generally show the transformer in the ceiling space above, and close to, the entry door. I put them on their own circuit, or share two nearby bathrooms on the same circuit. That is not because of loading concerns, for as you pointed out these things don't draw much current. It is for ease of maintenance, mostly. If you have to share with the lights or the receptacles, I would go with the receptacles, but I would connect the transformers upstream of the GFCI device.

 

[rcwilson]

One of North America's busiest airports, Pearson in Toronto, Ontario, Canada, was closed down by local health authorities during the Northeast Blackout a few years ago. Emergency generators kept some lights on and the planes flying safely on much delayed schedules, but all of the flush valves were on normal power with no manual flush capability. With thousands of stranded travelers, the mess became unsanitary very quickly and led to a shutdown and evacuation of the airport. (The incident resulted in a new back up generation facility).

Moral- if it is a larger public facility, consider putting those low power flush sensors on an emergency circuit.

 

[charlie b]

Moral- if it is a larger public facility, consider putting those low power flush sensors on an emergency circuit.

Very good point, Bob! I haven't done that on any recent projects - all bathroom circuits are on normal power (except perhaps an egress light). But in every facility I have designed recently, the owner did not want the occupants to continue working in the building, if the utility power were to be lost. The intent is to send the workers home. The design basis for the back up generator was limited to egress lights and other emergency loads, and to certain optional standby loads (e.g., enough receptacles to prevent the loss of experimental data for lab experiments in progress).

 

[iwire]

Moral- if it is a larger public facility, consider putting those low power flush sensors on an emergency circuit.

Strictly speaking it would have to be an optional standby circuit unless that area has 'legally required and classed' the electric valves.

But I agree with both you and Charlie that some sort of backup is good design.

 

[Zorch]

NP,

Get the specs on the power supplies/transformers. I've installed a few that were pre-assembled units that we weren't supposed to modify (UL thing). They had a short cord to the first sensor which necessitated putting the transformer under the sink just 36" from the first "lifesaver".