Contactors and Relays (anti vibration ?)

[joel89]

I have a panel, on our large hammer forge which causes a hell of a lot of vibration hitting a 5tonne tube, anyway I am loosing my retain on 2 x small contactors LC1 18a which feed a servo and lubrication system and when the tube is nearly forged into a bottle neck shape it also causes a small 5a plug in relay feeding some oxy propane burner solenoids, basic dol start stop pb circuit I was wondering if there is anything on the market that will create enough electro magnetism to stop this happening?? or stronger springs on the relays and contactors??

any advice would be great cheers !

 

[Bobster]

Solid state relay. No moving parts.

 

[D Skelton]

Solid state relay. No moving parts.

Are there SSRs capable of handling 18A?

Is it not possible to mount the control panel further away but retaining controls in their current position?

 

[davesparks]

Are there SSRs capable of handling 18A?

Is it not possible to mount the control panel further away but retaining controls in their current position?

Yes, from memory I think Crydom make them with ratings upwards of 100A.

 

[Marvo]

You get cam operated relays and contactors, I used them many years ago on a project and they basically use a coil which in turn operates a cam that rotates 180 degrees to actuate the relay/contactor, they're completely impervious to impact. I've also see mechanically latching contactors which require both a control supplyto latch and a supply to unlatch. I'll have to dig around my office PC on Monday to get the details of the ones we used which I think were 30A or maybe 50A.

 

[tazz]

Andy your showing your age, with mechanical switching...lol...
Solid state, or diac switching quite common in plant control, and can handle some high loads, but they dont have a long life span. Last one I worked on was a feature swimming pool, were pumps were timed and controlled from diac`s

 

[D Skelton]

Yes, from memory I think Crydom make them with ratings upwards of 100A.

Must admit, I've not had much call to use SSRs. Only ones I've used have been for low current applications, and normally to switch larger mechanical relays.

 

[Marvo]

Also, depending on the severity of the problem you could try re orientating the contactor/relays that are giving problems, sometimes turning them through 90 degrees so the shock force is perpendicular to the relay or contactor armature might stop contact bounce under shock vibrations.

 

[Marvo]

Andy your showing your age, with mechanical switching...lol...

I don't know with you youngsters, just because it won't synchronize with your Facebook and Twitter account doesn't mean it not fit for purpose

 

[ian.settle1]

Are there SSRs capable of handling 18A?

Is it not possible to mount the control panel further away but retaining controls in their current position?

SSRs are used in UPS panels which can switch large loads

 

[tazz]

Late 90`s they have become more common, to protect sensitive electronics. The more we use microprocessors the more protection they need. Back emf from relays and a unstable voltage etc can do some expensive damage, so designs are turning more to ss

 

[D Skelton]

SSRs are used in UPS panels which can switch large loads

Very true, they are indeed!

 

[tazz]

Some of us old folks have to keep up with change.....lol

 

[joel89]

Cheers for the replies, I am using 18a contractors I am switching a 1.5kw at 415v motor and a 0.37kw at 415v motor. 110v ac control voltage, moving the panel is too much work 95mm feeder 110kw motor and loads of external outgoing cables !

 

[Bobster]

SSRs under 100A have become pretty affordable. Still looking at 3x the cost of a standard contactor, but I guess cheaper than a breakdown.

 

[Darkwood]

Cheers for the replies, I am using 18a contractors I am switching a 1.5kw at 415v motor and a 0.37kw at 415v motor. 110v ac control voltage, moving the panel is too much work 95mm feeder 110kw motor and loads of external outgoing cables !

Use VSD's mounted on anti vibration mounts, no moving parts and more protection and control afforded.

 

[joel89]

Don't need a VSD, no need for variable speed atv 312s are £350 for a 1.5kw, I have a soft start for the main forge motor 110kw

 

[Darkwood]

It was a solution for your situe' ... not saying its speed control was needed etc, if you fit some form of SSR device its will still need semi conductor protection to boot and the cost start mounting.... plus you need to shop around a bit £350 for a 1.5kw is not a good deal... Ive just fitted a 1.5kw 1ph-3ph (output protected) £250 quid ..... note I put output protected because their is a range of budget drives out there that have dropped output protection without really telling you and giving what seems a deal and a half.

 

[joel89]

hmmm so a solid state is not wired the same as a dol start stop on circuit?

 

[joel89]

https://m.rs-online.com/h5/mobile/uk/catalog?url=/web/p/solid-state-contactors/8229357/

 

[Darkwood]

hmmm so a solid state is not wired the same as a dol start stop on circuit?

It is more or less but requires extra protection knowledge of the suitability of different types of SSR's for inductive loads ...you cannot just pick one up off the shelf and fit it if you don't know what the different natures of SSR devices are out there or you'll receive an expensive lesson plus you also still require motor protection in the form of a motor O/L device, now if this was afforded by a contactor mounted device then this will now be unsuitable and you need to purchase a stand alone unit.

EDIT just seen your link... this is a newish version of an SSR and yes looks suitable to me and gets around a lot of the issues Ive just mentioned by the looks of it... Ill still need to read up on its requirements for semi conductor protection.

 

[joel89]

Thanks dark wood I have telemec gv2 mccb protecting the motor and contactor and by the looks of the aux contacts looks like it has no and nc so might be an easy swap

 

[Darkwood]

Yes just looking at the protection of these devices and it does look like you need to still have Semi-conductor fusing ... it give faster S/C overcurrent protection to the SSC than standard fusing and most times will save it in the event of a S/C but like anything, it won't always. To note these devices like standard relays/contactors can fail closed so your operating system needs to have other means of taking the power out and a standard mcb may not protect the destruction of the SSC hence semi-conductor fusing required to save you having to change the whole thing everytime you get a fault.

You are fitting an electronic device so this was my concern about needing the extra measures to protect it from been destroyed when doing its job under a fault condition.

 

[joel89]

Yes I have an E-stop circuit in place, so would the small glass fuses do the job? Is it just to protect the control circuit or for the main 3phases??

 

[Darkwood]

Yes I have an E-stop circuit in place, so would the small glass fuses do the job? Is it just to protect the control circuit or for the main 3phases??

Its to protect the SSC or SSR from overcurrent associated with short circuits not the control circuit. - read the info supplied with said SSC you linked to - it explains the fusing and give make and sizes of semi-conductor fuse ratings to match the motor your supplying.... TBH with no disrespect here .. if your getting involved with this stuff you will become responsible for all the safety and operation of the system by making any upgrades or alterations or additions... as you are asking these questions I'm assuming your not clued up on the Low Voltage Directive or the BS EN 60204-1, you can change like for like as a repair but any upgrade addition or alteration then you need to do a full assessment on the existing to ensure it complies to modern criteria - you are putting a lot of responsibility upon yourself here without a leg to stand on, if someone is injured by this machine regardless whether it was nothing to do with anything you did then you been the last to make a alteration, change or addition to the existing are responsible and will be the man to answer why you didn't bring it in line with modern regulation when you was altering the controls as you would need to to correctly implement a SSC ..... you could omit the Semi-conductor (after a risk assesment regarding its failure) and class it as a like for like but any faults will require the whole SSC to be replaced everytime but the whole weight of responsibility won't be burdened as heavily on your shoulders if you can convince them its a like for like.

Other things to consider are if you are self-employed then your PL and PI insurance will need to know you are working both on machinery and 3ph systems ..if you have not informed them then you are not allowed to work on such systems because you are uninsured... if you work for a company ensure they are covered for your work.

 

[LeeH]

I would suggest moving the panel if the vibration is as bad as you describe.

Or mount panel on anti vibration mounts, I have done this in the past.

Sometimes the obvious solution can get overlooked

 

[joel89]

I have fitted anti-vibration rubber under the panel still the same.. have to think of another idea

 

[Marvo]

Did you check that the voltage isn't dropping significantly when the forge hammer operates?

 

[joel89]

I haven't no Marvo but it cant be as the large 400a contactor and altistart soft starter are not dropping out and the hammer its self carries on running and never trips/ looses retain circuit !

 

[topquark]

If the activation is rectified to DC internally (which they often are) the VD on 110V AC when rectified may be enough of a drop off to loose the field.