Help needed - identify traction motor cable connectors?

[RobjUK]

Hi,

does anyone know what this style of two-bolt cable connector lugs are called - ie. what to search for to find a supplier of compatible parts?

I've searched under every description I can think of and not been able to find anything similar, with solid bodies rather than just flat tags.

 

I'm rewiring a vintage English Electric built tram and these are used for the connections to the bogie traction motors.

The owners interchange bogies for maintenance, so the connections need to be compatible; I can't just replace both sides with standard single hole terminal lugs.

 

As a last resort I can try to remove the connector lugs from the previous cables but a source of new ones would be very useful!

 

Thanks, Rob.

[iands]

Don't know if you have already looked at this web site, but in the following link if you scroll down the page to the last picture there are a number of connectors, some are even the "solid" variety with two bolt holes. Not sure if they are correct rating or physical size you need but worth investigating further on this companies product page.

 

Hope it helps.

 

https://www.epowerrail.com/Products/CategoryElectrical/SubTerminal-Lug?Sub=Terminal - Lug&Category=Electrical

[Davexoc]

As they don't appear to be crimped, I am guessing they are soldered on. So your best bet is to get out a blow torch and reuse them.

[jim.snowdon]

They almost certainly are soldered, as that was a standard (if not the only) method until well into the 20th century. They're probably also an EE standard so would be found on other EE traction motors.

 

They will be reusable by unsoldering from the leads, cleaning them up and resoldering to new leads. That's exactly what we did with the older London Underground motors (older = up to at least the 1972 tube stock, if not later) whenever they needed leads renewing.

 

Apologies if you have done this already, but making enquiries of Blackpool Tramways, or the likes of the National Tramway Museum might prove worthwhile.

 

Jim

[RobjUK]

@iands - thanks for the link, there are some interesting ones there, I'll have to see if there are any with appropriate dimensions.

 

@Davexoc & jim.snowdon - I realise the existing ones are soldered, I just don't routinely carry my 150W iron or a blowlamp in my toolbox...

 

The main reason I was hoping for a source of new ones is that the amount of heat needed to properly flow terminals that size does not do PVC cable much good, it's not like an electronics joint where you only need heat for a second and it can't travel far in that time.

 

A good crimped connection is much faster, neater & no burning plastic fumes.

Edited May 21, 2019 by RobjUK

[jim.snowdon]

I'd agree - it won't do PVC insulated cable much good, but then, all of the cables on our traction motors were CSP insulated (synthetic rubber, in simple terms), not least because traction motors do get rather hot - Class H insulation was normal. Without knowing any more about yours, I would actually be wary of using PVC insulated cables at all.

 

Jim

[roythebus]

They seem similar to the old flat type connectors used on London Buses (RT/RF/RM) battery leads. they were made from cooper tube flattened at one end, holes drilled and the cable soldered in. The flattened end prevented the molten solder running out. 

 

I'm certain I've seen these connectors on more modern buses as well.

[roythebus]

Just thought, I'll ask my son, he's fleet engineer for the Southern!

[jim.snowdon]

2 hours ago, roythebus said:

Just thought, I'll ask my son, he's fleet engineer for the Southern!

Nearest match might be the connections on the EE507 motors fitted to Southern's 455 units, but, they might equally by a larger size, as they are 250hp motors.

 

Jim

[jim.snowdon]

As a further thought, if you end up drawing a blank, you could do worse than have a chat with a company like Cembre, who manufacture all manner of crimp terminals from small to the 1000 sq mm ones used for conductor rail connections (and with whom I have no connection other than as a user).

 

Jim

[roythebus]

My son says they use this firm for such things:  https://www.anixter.com/en_us/search/?text=traction+motor&searchFlag=true

 

[RobjUK]

20 hours ago, jim.snowdon said:

it won't do PVC insulated cable much good, but then, all of the cables on our traction motors were CSP insulated (synthetic rubber, in simple terms),

Hi Jim,

 

The motors in the bogies are fitted with flying leads & the groups of connector in the body/chassis are well anchored within a foot or so of the cable ends, so fairly well isolated from any motor heat.

 

The cable we are using is 150'C rated as well so I don't see any operational problems in that regard, just cosmetic with the soldering heat.

 

Stripping the old connectors down ready for desoldering was almost like an mini archaeological dig - many decades worth of differing types of insulating tapes, from PVC through sticky fabric to gutta percha or similar soft rubber & revealing the original cotton braided rubber cable - then the extremely weedy looking copper core in that; it's supposed to be the imperial equivalent of 25mm^2 according to the original drawings, though it seems rather smaller..

 

 

[Ceptic]

https://uk.search.yahoo.com/search;_ylt=AwrJQ5tufeZciUMANmsM34lQ;_ylc=X1MDMTM1MTIxMjgxMgRfcgMyBGZyA21jYWZlZQRncHJpZANKaW40Z0ZUVFJENklTMkhlemtVWFlBBG5fcnNsdAMwBG5fc3VnZwMwBG9yaWdpbgN1ay5zZWFyY2gueWFob28uY29tBHBvcwMwBHBxc3RyAwRwcXN0cmwDMARxc3RybAMzOARxdWVyeQN0d28lMjBob2xlJTIwY2FibGUlMjBjb25uZWN0aW5nJTIwbHVncwR0X3N0bXADMTU1ODYwOTM0OA--?p=two+hole+cable+connecting+lugs&fr2=sb-top&fr=mcafee&type=E211GB128G0

[Zomboid]

18 hours ago, RobjUK said:

 - then the extremely weedy looking copper core in that; it's supposed to be the imperial equivalent of 25mm^2 according to the original drawings, though it seems rather smaller..

With solid cables (ie pi*r*r), 25sqmm gives a radius of less than 3mm. That's obviously stranded so it'll be a bit bigger, but not by that much.

 

The actual size of the conductors always surprises me though until I actually do the calculation...

[jim.snowdon]

I have to admit that, from the pictures, they don't look like 3-3.5mm diameter. Are you really sure they are as small as 25 mm^2?

 

EE weren't exactly known for watchmaking either when it came to traction equipment and motors - all of their kit was pretty solidly engineered, more so than their usual competitors.

 

Jim

[Zomboid]

3mm radius. They'd be 6mm-ish diameter.

 

It's hard to say without a proper scale, but they look about that size to me.

[jim.snowdon]

2 hours ago, Zomboid said:

3mm radius. They'd be 6mm-ish diameter.

 

It's hard to say without a proper scale, but they look about that size to me.

I'd agree - I fell for the perils of trying to do the calculation without writing it down, as in forgetting that the answer would be the radius,not the diameter. 

 

Jim

[RobjUK]

7 hours ago, Zomboid said:

With solid cables (ie pi*r*r), 25sqmm gives a radius of less than 3mm. That's obviously stranded so it'll be a bit bigger, but not by that much.

 

Yep, it could just be that I'm not used to working with such coarse stranded types... We normally only use tri-rated cable in the general gear we work with, which looks rather larger when stripped.

 

I'll try the old wire in a 25mm crimp tomorrow, just out of curiosity...

 

 

Re. the other answers & links - thanks, I've found many different pressed crimp lugs but none with the rigid structure or matching dimensions of these. The original set are getting re-used.

 

ps. To clarify, we are rewiring the body & chassis, not the actual bogies/motors - the connectors we are working with are in the body, to match up to the existing bogie motor tails.

 

[roythebus]

The way to solder these on is to clamp the connector upright in a vice, heat with a blow lamp and fill it with solder, then insert the bared cable. That way the whole thing gets immersed in solder and the insulation doesn't overheat. I've used this method for bus battery cables. Just don't use flux with the solder.

 

But check the tube bit that the cable goes in is solid at the bottom!