Valve coil surge supressors

Rick Densing · Mar 10, 2005

I am looking for surge supressors that I can install on existing hydraulic valves. Installation would be to sandwich them between the connector and the valve. 120VAC
Anyone have a good source. I have found these, but the lead time is long.

Thanks.

elevmike · Mar 10, 2005

Rick Densing said:
... Installation would be to sandwich them between the connector and the valve.

Rick,

Not really sure what your looking for but, we install surge suppressors right on the terminal strip where the valve coil leads connect. We use the typical disk type mov, rated for whatever is necessary. Their about 50 cents apeice. Cant think of the part no right now but we buy them by the dozens at Galco.. (good for a choclate bar). Radio Shack sells 130 volt Movs also..

kamenges · Mar 10, 2005

I thought an MOV will only take a finite number of 'hits' before it will be destroyed? If this is true how do you tell if it is destroyed and needs ot be replaced?

Keith

CaseyK · Mar 10, 2005

Rick: Those are pretty slick looking units.

Mike, that is how I'v usually done it in the past. Did have one customer that bought really expensive receptacles, had us disassemble them, install 3 mov's, and reassemble them. Kinda ruined UL acceptance, but he was a Registered PE.....

Keith: When I put mov's on for lightning or HV protection, it is obvious. The leads are usually all that is left. On plc outputs (120v), it seems like a couple of good hard hits, and they discolor or crack somewhat. I am sure that this would vary with different plants environmental conditions, and the operarating voltage. With 24v (actually, when customer is buying) I like GE's RC unit, but they ain't cheap.

regards all.....casey

Mtn_Bkng_Dave · Mar 10, 2005

Rick,

Can't remember the manufacturer but I used to get them integrated into the cordset. They weren't much more than the standard cordsets and were readily available. Let me know if you are interested and I can possibly get you some more info on them.

Dave

elevmike · Mar 10, 2005

Keith,

MOVs are rated by the crossover voltage, and Joules. So lets say your device your trying to protect is rated at 24volts, then you might want a 30 - 35 volt mov. Next you need to decide how much energy, (watts or joules) might be developed by a collapsing starter or valve coil and size up the MOV by 20% or so.. As far a lighting strikes go...well you'd be lucky to get two chances at it.. Otherwise it should last indefanitly.

Johnny Rotten · Mar 10, 2005

So you want to 'contain' the high voltage induced when the valve coil is de-energized? What are you trying to protect? How many step-down transformers are between this machine and power coming into your building?

Did your Electrical Inspector ask for this?

If your valves are 120VAC its not much of a problem. AD says you have a 1 in 60 chance of transients when a 60Hz coil de-energizes. That could be argued.

Protect what ever you think should be protected. If you have an expensive HMI etc... protect that. Most PLC's have zero issues with AC Coil Collapse.

80% of transients are produced internally
20% of transients are produced externally

Its the 20% you want to worry about.

Johnny

Rick Densing · Mar 11, 2005

I have a customer that is burning out Pheonix inline I/O relay outputs on an existing machine. Phoenix has confirmed that the outputs have the capacity to actuate the valves. However, the did recommend the surge supressors. This is the easiest way to install them with minimal downtime, plus it puts the unit close to the coil.

TOMC · Mar 11, 2005

Have a look at these guys. I have used some of there stuff in the past the quality is good and the prices were resonable.
www.murrinc.com

stevo · Mar 11, 2005

Just to elaborate on TOMC's suggestion, we use these units Suppressor/LED status units quite alot on our Pneumatic stuff, Maybe this is what you are looking for?

http://www.murrinc.com/en/products/catalogue/index2.php?PDFShop=0e31162620eb24d7465ea21f9e738067&pdf=3_6.pdf

Hope this helps

Steve

Rick Densing · Mar 11, 2005

I thought the murr stuff would do the trick, however I found a snag. The valves are wired with connectors that go to both valves at once and the dongle that sticks up the side will hit it.

mike5120 · Mar 11, 2005

hi.
Try on

http://www.lutze.com/lutzeus/catalog/index.htm

Hope this helps
mike

foamman · Mar 12, 2005

I use Canfield Connector for all my DIN needs.

http://www.canfieldconnector.com/solenoid_connectors.htm#p5600

Aquadevel · Apr 26, 2005

You don't want 'MOV's' across a valve solinoid, just use a diode, as you would for relays.

Rick Densing · Apr 26, 2005

Aquadevel said:
You don't want 'MOV's' across a valve solinoid, just use a diode, as you would for relays.

You trying to let all the smoke out of the diodes at once? I said 120VAC.

Valve coil surge supressors

Rick Densing

Member

elevmike

Member

kamenges

Member

CaseyK

Member

Mtn_Bkng_Dave

Member

elevmike

Member

Johnny Rotten

Member

Rick Densing

Member

TOMC

Member

stevo

Member

Rick Densing

Member

mike5120

Member

foamman

Member

Aquadevel

Member

Rick Densing

Member

Similar Topics