How can I connect a pump controled via 3 independent switches?

[BMW]

Hi
Need some advise. Got a customer who has a air pump switched via a switch fuse. It's a dentist and the pump feeds air to 3 work benches. Now he wants the pump switched by 3 indipendent switches at each bench rather than the one.

I'm thinking a contactor /relay between the mains and pump a switch fuse on the live side then fusing down and wiring the 3 switches like a domestic instalation (2-2 way and an intermidate switch) this feeds the coil to the contactor / relay. That way each switch will turn the pump on and off. The switches can be normal as they are only switching the coil not the load.

Can anyone who has the relative experience see anything wrong in my suggestion. I am a Qualified sparky but this is out of my normal area of work and being on my own have no one to bounce ideas off. Can anyone help.

Cheers

 

[RogertheBodger]

Sounds OK to me, put the contactor between the switch fuse and pump (think that's what you meant), three one way switches in parallel would do the same job.

 

[jumpin jax]

Use grid, 2 x 2 way switches and an intermediate

 

[sedgy34]

Hi
Need some advise. Got a customer who has a air pump switched via a switch fuse. It's a dentist and the pump feeds air to 3 work benches. Now he wants the pump switched by 3 indipendent switches at each bench rather than the one.

I'm thinking a contactor /relay between the mains and pump a switch fuse on the live side then fusing down and wiring the 3 switches like a domestic instalation (2-2 way and an intermidate switch) this feeds the coil to the contactor / relay. That way each switch will turn the pump on and off. The switches can be normal as they are only switching the coil not the load.

Can anyone who has the relative experience see anything wrong in my suggestion. I am a Qualified sparky but this is out of my normal area of work and being on my own have no one to bounce ideas off. Can anyone help.

Cheers

yep you will be ok doing that

 

[telectrix]

be better to use 3 1 way switches in parallel. if yo went the 2 way/3way route, bench 1 could be in use and the guy at bench 2 could inadvertently switch off bench 1, thinking he was turning his bench on.

 

[Darkwood]

Sounds OK to me, put the contactor between the switch fuse and pump (think that's what you meant), three one way switches in parallel would do the same job.

Three one way switches in parallel wouldn't be a good design if more than one switch was on then the pump wouldn't turn off by operating just one switch causing confusion, it would funtionally work but only if used one switch at a time.

Edit... soz rog re-read OP i see its 3 independant benches i pump so yes agree without going the the expense of a start/stop control system with bench indication which would be more suitable but alot more costly.

 

[Knobhead]

So long as they don’t want “pump running” indication at each bench, three single switches is the way to go.

If they do want indication then I’ve done a drawing which I’ll post if you ask.

 

[J&M Electrical]

So long as they don’t want “pump running” indication at each bench, three single switches is the way to go.

If they do want indication then I’ve done a drawing which I’ll post if you ask.

I'd be interested to see this tony, just for future reference and you can never stop learning.

 

[Knobhead]

Here you go

View attachment 12095

 

[Guest55]

nice drawing.
wish i had some cad program on my laptop lol.

 

[Knobhead]

You’d regret it if you had the one I have.
It was written for Windows 3.11
Over the years I’ve built up a library. I can chop and change drawings as required.

 

[Silly Sausage]

Here you go

View attachment 12095

I'd extend the design so far to include a solenoid valve on each air line to each bench.
Replace the SP switches with DPs, the 2nd pole to energize the solenoids.

 

[Guitarist]

Don't forget to mail Tony £1000 design and consultation fee.

 

[Darkwood]

nice drawing.
wish i had some cad program on my laptop lol.

PCSCHEMATIC - software for automation, electrical installation, hydraulics and pneumatics
Download this its free, un-timelimited as long as you are not doing over 10 pages, more than 40 symbols or 200 connections.... took me a weekend of playing about now i can draft up most things.
check http://www.electriciansforums.net/e...e-joined-incomer-your-house-4.html#post510832 (my post 55!) id did the pdf's on it and only had it a week and no instruction needed.

 

[parker56]

Tony when do you sleep?what ever time I log your here.lol

 

[Knobhead]

I'd extend the design so far to include a solenoid valve on each air line to each bench.
Replace the SP switches with DPs, the 2nd pole to energize the solenoids.

Typical tiffy! Over complicate things!

 

[Knobhead]

Tony when do you sleep?what ever time I log your here.lol

Insomnia

View attachment 12096

 

[Silly Sausage]

Typical tiffy! Over complicate things!

No comment...
well, complicated for a HV tech, maybe; no finesse you chaps :tounge_smile:

 

[Knobhead]

Touché.

We do have our delicate side at times.

 

[Silly Sausage]

I know you've been teasing for weeks, my soft spot gave in!
Round 2...

 

[Knobhead]

Come on, the needling between electrical technicians and instrument artificers has gone on for the last forty+ years I’ve been kicking around in the industry.

Electrical technicians were always the higher paid, we could do both jobs!