Wanted SPDT Relay 12 volt / 50 Amp

lenseman

lenseman

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www.dswmarineengineering.com
Can anyone tell me a supplier of a relay of the above type?

It has to be 30 Amp continuous current SPDT rating and as such the Lucar terminals just will not do. Sadly, salesmen try and fob you off, little do they know that the Lucar will only handle 30 Amp Max! What they fail to grasp is that although the male terminal on the relay will handle the current, over time, the female Lucar to which it connects will anneal and become loose which, at these sort of currents, can be catastrophic. :eek:

The previous person to rewire this boat had no idea and used large 'chocolate blocks' to handle the circuit and on close inspection the chocolate block are rated at 15 Amps. The 16 Amp switch also melted (some of you will remember me trying to find one 15 months ago). :(

Before anyone jumps in, CPC-Farnell sell relays but they have Lucar and not screw terminations:

http://cpc.farnell.com/finder/65-31-9-012-0300/relay-spst-12vdc/dp/SW04023?Ntt=65.31.9.012.0300

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pvb said:
That's a contactor, not a SPDT relay!
Click to expand...

Seems I'd misread it as SPDT when it's actually two independent poles. Although I think there's a SPDT one in the same series.

Isn't "contactor" just a different word for a big relay?

Pete
 
lenseman said:
Can anyone tell me a supplier of a relay of the above type?

It has to be 30 Amp continuous current SPDT rating and as such the Lucar terminals just will not do. Sadly, salesmen try and fob you off, little do they know that the Lucar will only handle 30 Amp Max! What they fail to grasp is that although the male terminal on the relay will handle the current, over time, the female Lucar to which it connects will anneal and become loose which, at these sort of currents, can be catastrophic. :eek:

The previous person to rewire this boat had no idea and used large 'chocolate blocks' to handle the circuit and on close inspection the chocolate block are rated at 15 Amps. The 16 Amp switch also melted (some of you will remember me trying to find one 15 months ago). :(

Before anyone jumps in, CPC-Farnell sell relays but they have Lucar and not screw terminations:

http://cpc.farnell.com/finder/65-31-9-012-0300/relay-spst-12vdc/dp/SW04023?Ntt=65.31.9.012.0300

.
Click to expand...


If you look at this link (I know it is US) it does claim to be 50 amp continuous but has Lucar terminals

http://www.texasindustrialelectric.com/relays_0332209138.asp

If you are concerned about the electrical connection, you could look at using bare female :) terminals and then solder the connection followed by making them safe with heat shrink.

However, there is perhaps another way to get your SPDT configuration with screw connections and that is to use two of these with the individual coils fed from a 'SPDT momentary switch' with a centre off position

http://www.ebay.co.uk/itm/12V-4-PIN...arts_Vehicles_CarParts_SM&hash=item337e56dd0a
 
chrisbitz said:
you could try http://uk.rs-online.com

and I think http://uk.farnell.com/ is slightly different to CPC too?

and of course, haven't you tried Maplin? :-)
Click to expand...

I am an account holder with both CPC and RS but neither supply a relay at 30 Amps continuous with screw terminals. Maplin don't even know what 30 Amps is, they usually only deal with the hobby market where 1 Amp is high power! :(

.

prv said:
This do you?

http://www.thetoolboxshop.com/sw82-...-solenoid-contactor-12v-continuous-5251-p.asp

100amp continuous according to the data sheet.

Pete
Click to expand...

Hiya Pete, an interesting set of switches but on careful examination of the data sheet, these relays are rated at 100 Amp continuous 180 Amp peak, BUT on the bottom of Page 2 it states that these relays re NOT designed to make or break current ?? Furthermore, they look to be latching which is not what is required and I suppose the hold in current on the coil will possibly be measured in Amps? :(

Jcorstorphine said:
If you look at this link (I know it is US) it does claim to be 50 amp continuous but has Lucar terminals

http://www.texasindustrialelectric.com/relays_0332209138.asp

If you are concerned about the electrical connection, you could look at using bare female :) terminals and then solder the connection followed by making them safe with heat shrink.

However, there is perhaps another way to get your SPDT configuration with screw connections and that is to use two of these with the individual coils fed from a 'SPDT momentary switch' with a centre off position

http://www.ebay.co.uk/itm/12V-4-PIN...arts_Vehicles_CarParts_SM&hash=item337e56dd0a
Click to expand...

Thank you for the suggestions BUT the Bosch relay is rated as PEAK at 50 Amps which means continuous at 25 Amp, hence the Lucars. I have been on the phone most of the day talking to a load of technical engineers about this problem. We are talking CONTINUOUS 30 Amps and I dont want to have to re-wire my yacht again. A Muppet did the wiring for the previous owner, and this Muppet had no idea about current ratings hence the major burn out.

I will certainly contact the other company in the morning (ALM Electrical Solutions), thank you.

The trouble is when the state 50 Amps, you think Great :D but they don't state that is PEAK rating! :mad:

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David, what is the application ?

Possible to use a light duty switch or relay driving SPST relays ?

If so a couple of the lucas 33RA relays with M5 terminals
 
starfire said:
David, what is the application ?

Possible to use a light duty switch or relay driving SPST relays ?

If so a couple of the lucas 33RA relays with M5 terminals
Click to expand...

I spent the afternoon at Donovan's Electrical in Gosport and they are Marine Electrical contractors. We went through a number of relays and I mentioned Lucas (as I was an RAC Engineer in a previous life, back in the late 70's). He said Lucas don't exist anymore?

Do you have any details of the Lucas 33RA relay, the only relays I used to deal with were Lucar which accepted the obsolete Ripaults terminals? :)

You now have to use the Red, Blue or Yellow crimp terminals and the Yellow ones are rated at 30 Amp Max. :eek:

.
 
Found one closer but is still not overnight :(

lenseman said:
POOPS !! Just seen they are Chinese relays, shipping from the Far Flung which probably means January delivery not withstanding being held in Customs until I pay the duty! ::mad: I need them this week! :eek:

This of course assumes they really are 60 Amp ? :confused:
Click to expand...

Found this as well

http://www.amazon.com/Reversing-Continuous-Solenoid-Relay-Windlass/dp/B004VAGKZE

But it is US but looks pretty heavy. Howver, I think it is powered to make bothe poles so is not a stratight SPDT.
 
Jcorstorphine said:
Found this as well

http://www.amazon.com/Reversing-Continuous-Solenoid-Relay-Windlass/dp/B004VAGKZE

But it is US but looks pretty heavy. Howver, I think it is powered to make bothe poles so is not a stratight SPDT.
Click to expand...

A very strange device, four H/D terminals plus two small Lucars for the coil?

It would be nice to have a simple cct diagram, but it states DPDT.

Again it is in the USA so not much use this week. :(

BLIMEY!!! :eek: I just looked at their shipping costs for that item to Europe . . . . . $79.99 !! No thanks :mad:

.
 
lenseman said:
Hiya Pete, an interesting set of switches but on careful examination of the data sheet, these relays are rated at 100 Amp continuous 180 Amp peak, BUT on the bottom of Page 2 it states that these relays re NOT designed to make or break current ?? Furthermore, they look to be latching which is not what is required and I suppose the hold in current on the coil will possibly be measured in Amps? :(
Click to expand...

Dunno what the "not make or break current" is about. They'd be pretty useless if that were true. I have one as part of my battery charging system and that certainly makes and breaks 60 amps of charging current ok.

Some models in the range may be latching; mine isn't and I assume most of the others aren't either. Note that the specific one I linked to is probably not the type you need; the datasheet lists the fuller range towards the end.

Large coil current you may have a point. I don't really know what it is, but my charge controller uses PWM to reduce the overall power used. If they bothered doing that then I guess it must be substantial :(

Pete
 
starfire said:
David, I think he maybe right,
The one I was thinking of was the Lucas SRB630


Possible this durite one may be over kill.

http://www.thetoolboxshop.com/0-727...ra-heavy-duty-make-and-break-relay-2128-p.asp
Click to expand...

The problem is that the OP was looking for a SPDT, the Durite one is a SPST

As I understand the OP needs, he is looking for a relay which gives power though to connection 'A' with no power on the coil and power through to connection 'B' with the coil energised. In other words he requires a two pole relay with a normally closed contact and a normally open contact. (I THINK)
 
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