220 volt switching
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Posts: 46,084
Hi group,
I need to control some industrial equipment rated at 220 vac @40ampere.
Normally some heavy duty relays are used to just shut it on and off. I was
wondering if anyone had any experiance switching a heavy load like this.
Should I use a solid state relay? or make one from semiconductors or even go
with a electro-mechanical relay. The switching will only be on and off, and
nothing rapid. I am using a BSII to control it. Any ideas for a practical and
cost effective means?
Thanx
I need to control some industrial equipment rated at 220 vac @40ampere.
Normally some heavy duty relays are used to just shut it on and off. I was
wondering if anyone had any experiance switching a heavy load like this.
Should I use a solid state relay? or make one from semiconductors or even go
with a electro-mechanical relay. The switching will only be on and off, and
nothing rapid. I am using a BSII to control it. Any ideas for a practical and
cost effective means?
Thanx
Comments
(they don't list input current). It is an SCR type rated to 280vac and 50
amps. Digikey part no CC1045-ND, $34, made by Crydom. Just make sure your
load doesn't have an inrush current exceeding the 50 amps. Catalog page
482.
www.digikey.com
Ray McArthur
Original Message
From: <electronguy@a...>
To: <basicstamps@egroups.com>
Sent: Monday, August 21, 2000 5:38 PM
Subject: [noparse][[/noparse]basicstamps] 220 volt switching
> Hi group,
>
> I need to control some industrial equipment rated at 220 vac @40ampere.
> Normally some heavy duty relays are used to just shut it on and off. I was
> wondering if anyone had any experiance switching a heavy load like this.
> Should I use a solid state relay? or make one from semiconductors or even
go
> with a electro-mechanical relay. The switching will only be on and off,
and
> nothing rapid. I am using a BSII to control it. Any ideas for a practical
and
> cost effective means?
On Mon, 21 Aug 2000 17:38:27 EDT electronguy@a... writes:
> Hi group,
>
> I need to control some industrial equipment rated at 220 vac
> @40ampere.
> Normally some heavy duty relays are used to just shut it on and off.
> I was
> wondering if anyone had any experiance switching a heavy load like
> this.
> Should I use a solid state relay? or make one from semiconductors or
> even go
> with a electro-mechanical relay. The switching will only be on and
> off, and
> nothing rapid. I am using a BSII to control it. Any ideas for a
> practical and
> cost effective means?
>
> Thanx
>
>
>
are talking about a 220VAC SINGLE phase system? Some good contactors are
put out by Siemens, ABB, GE or Struther's Dunn. You will also need slave
relays that will actually interface with the BS2 since the BS2 can only
source a max of 25ma. I suggest connecting your BS2 to a NPN transistor,
which will inturn switch a ground for a slave relay. The slave relay will
then pull in the contactor.
A good 5v slave relay is the LKS series by Aromat. I've used this one
before and it works well. However, any 5v slave relay will do as long as
the contact ratings are within the range of the contactors coil rating that
you pick out
Hope this helps and good luck.
Steve Tatum
Original Message
From: agarb@j... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=xI9ZdVdSwUEv7TydGc6fuyaoqWOPgoYqxq65rzPiDZlPl3xartHEMKY5UPrEyIRAdVN2Oed5RGK4]agarb@j...[/url
Sent: Monday, August 21, 2000 8:15 PM
To: basicstamps@egroups.com
Subject: Re: [noparse][[/noparse]basicstamps] 220 volt switching
How about a contactor?
On Mon, 21 Aug 2000 17:38:27 EDT electronguy@a... writes:
> Hi group,
>
> I need to control some industrial equipment rated at 220 vac
> @40ampere.
> Normally some heavy duty relays are used to just shut it on and off.
> I was
> wondering if anyone had any experiance switching a heavy load like
> this.
> Should I use a solid state relay? or make one from semiconductors or
> even go
> with a electro-mechanical relay. The switching will only be on and
> off, and
> nothing rapid. I am using a BSII to control it. Any ideas for a
> practical and
> cost effective means?
>
> Thanx
>
>
>
Are the loads you are switching motors and if so are they 3 phase?
Normally one would use a standard motor starter contactor ( that is a big
relay :-) ) with a 110 vac coil and that would be switched using smaller low
power relays such as octal base or the subminiature cube types which would
have 5 vdc or 12 vdc or 24 vdc coils in them. This has been a time proven
cost efficient and very reliable method of controlling higher voltage and
current loads. Of course one must use the proper RC snubbing network across
the coils of the motor contactors and a reverse diode on the coils of the dc
relays.
Solid state relays would work but would likely not be as reliable nor would
they be able to switch the 3 phase loads. However if the load is a single
phase on then the solid state relay would be much more attractive.
Hope this helps
Randy
Your example works well also for 3 phase applications since you are only
switching the coils of the contactors. I do that all the time. By the way,
W.W. Grainger carries the Telemecanique line of motor control devices and
some are not all that expensive, depending upon the loads of course.
Hope this helps too.
Randy A.