Outdoor MultiCable Outlet Issues

[SirKnightCowboy]

Hey Guys & Gals,

I'm working as the ME at an outdoor theatre; an amphitheater to be specific. In this space, there are many outdoor "weather proof" boxes with 1 to 4 MultiCable Outlets (19pin) spread out in various locations. My first problem is that the 9th pin in multiple of my outlets are burning out in what appears to be arch damage. When the first burn out happened, I figured it was due to a loose connection, so I had my crew go around a make sure all the connections were as tight as possible. Then it happened 3 more times within the next month and each time it was the 9th pin. My first questions are: Is this just a coincidence? What could be causing this?

Today I was finally able to get a little time to try and replace the connectors. I opened the box, unscrew the housing and saw that out of the 19 terminals, only 13 of them had wires soldered to them (6Hot, 6Neutral, and 1Ground). Terminals 1-13 were used and the 14-19 ground terminals were untouched on all 4 connectors. I know they make 12/14 Multis and 12/18 Multis but using only 1 ground for 6 possible circuits seems a bit sketchy. So my final questions is: for lack of a better term, Is this wiring kosher? If not How can I fix this?

I can upload more pic's if requested.

 

[FatherMurphy]

One rule of thumb is that ground should 10% of the capacity of the neutrals, so that might be where the installing electrician came up with the single ground. However, double grounds in a flexible cable is a very good idea, so the electrician should have at least bonded the 13 and 14 receptacle pins together, to pick up both cable conductors (assuming that the cables use 13 and 14).

Regarding your burning pins - did this happen all at once during one set-up, or is it possible you have one bad cable that's getting moved around, infecting other receptacles? Multiple cables and receptacles all burning the same pin would be rather wierd, but if you've got a bad cable that's placed in a different spot each show, that could explain it. If the bad pin was at the top, it would be more likely to be tightness related (as the weight of the connector pulled down and out on the top pins).

 

[DavidNorth]

I opened the box, unscrew the housing and saw that out of the 19 terminals, only 13 of them had wires soldered to them (6Hot, 6Neutral, and 1Ground). Terminals 1-13 were used and the 14-19 ground terminals were untouched on all 4 connectors. I know they make 12/14 Multis and 12/18 Multis but using only 1 ground for 6 possible circuits seems a bit sketchy. So my final questions is: for lack of a better term, Is this wiring kosher? If not How can I fix this?

It looks like you have a ring connecting all the ground pins on the inner ring [pins 13-18]. If so, then the inner ring is properly connected to what are assuming is ground on the green wire.

It is very odd that the same pin keeps burning out. I would look at the breakouts or multis that are being plugged into the females. It could be that the breakouts have corroded or burnt pins thereby reducing the surface area of contact and increasing the current load through that small area - in other words, overheating and burning out that pin. I think you have one bad cable or multi that keeps getting moved around.

Also verify that the breakouts and multis have good connections for the full circuit. Pin 9 is the hot for circuit 5. Make sure pin 10, the neutral for circuit 5, is good, healthy and in place. I can come up with multiple mis-wiring scenarios that put a lot of current on that pin but only if there are multiple wiring issues at the same time.

When these circuits are all connected up, do you have discreet control over each individual circuit? Hot up all 6 circuits and then one at a time cycle each breaker off and back on. Only one circuit should go dead at a time and no other lights should get brighter or dimmer. If not, then there are a couple of wiring errors.

Hope this starts you off on the right path.

David

 

[PeteEngel]

What is the physical alignment of the mult-connector? Is that pin at the 6 o'clock position? it looks like there is a bit of a lip on the inside of the case where the connector mounts. could there have been some water infiltration/humidity build up/cricket carcasses? weatherproof boxes aren't always that, especially after many seasons.

 

[DavidNorth]

Hmmm, and it looks like this is pin 10 [neutral] not pin 9. Am I counting wrong?

To be honest, this could be as simple as a bad female socket in location 10, it burned a male pin, then that burned male has been plugged into the other females and is slowly burning them.

David

 

[SirKnightCowboy]

Thanks everybody so much for your great advice.

David, You are right it does have a ring connecting all the grounds together. However, all mults were installed mid May for a season long show. So there has been no shuffling of cable on my watch. That doesn't mean that in years past, that that cable wasn't used in all these outlets. I did find a male pin that may be the culprit. It could just be now after the majority of damage was done, time took its corse and they are now deciding not to work.

As for poorly made connections I haven't checked the breakouts. The connections feeding the outlets are now all made and tight after having pulled one out myself by accident. also I do have discreet control over all my circuits.

Pete, As for weathering and condensation, it is most likely a possibility. Hence, "weather proof" in quotations.

I have a few more photos that I've attached to this reply. That should clear a few questions up.




I think my course of action will be clean all connections and replace the bad male Soca head and the bad outlets (sockets).

Here is my next problem, the spare panel sockets I have do not have a ring that connects the grounds. I have an idea but I want to know your opinion. See pictures below.



Tell me if I'm crazy, but I would like to solder that little wire star to each of the grounds to take the place of the ring in the old socket.

Thanks Again Everyone.

 

[derekleffew]

... Tell me if I'm crazy, but I would like to solder that little wire star to each of the grounds to take the place of the ring in the old socket. ...

Buy the right thing: http://www.controlbooth.com/forums/lighting-electrics/25756-photos-socapex-ground-ring.html .

You need to install a grommet or bushing or nipple, chase to project your multi-cable's jacket from the sharp edges of the holes in the enclosure.
.

 

[DavidNorth]

Seems like the right thing to do is exactly what you've said - replace the ends and double check the rest of the rig.

And I agree with Derek that you should just use the rings and get some protection for the jackets. The connectors do not ship with ground rings as the connector is generic, but when used for lighting, the ring is a desired assembly tool.

Soldering a jumper in there is going to be very difficult to do as you will need lots of concentrated heat to deal with the mass of the wire and pins. Speaking as someone who has hand soldered a lot of Veam connectors, this work is tricky and I think soldering six pins will be prone to cold solder joints. Certainly having a good ground connection is important on an outdoor rig. Are any of your circuits GFCI protected, by chance?

Grommet strip is a nice sheet metal edge protector, it's cheap and it's easy to install. We use it quite a bit.

Let us know how it goes,

David

 

[SirKnightCowboy]

Thanks again guys,

The proper parts have been ordered and should be here by Monday. I didn't realize the grounding ring was a separate piece. I thought we ordered the wrong sockets. When I do get the rings, how exactly do I secure them to the sockets? Tack it to a couple pins with solder, tack it to all of them, or does it just stay in with friction?

Oh and as for the GFCIs.. they are a no go. Just plain ole Sensor Dimmers from 2003 according to the date stamped on them.

 

[jstandfast]

Generally, the grounding rings pressure fit around the pins. You'll need a small,blunt tool end to help seat the rings.
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[JD]

Still interested in the pin #9 issue. If the cables are not swapped around much, is there a particular unit or type of unit that ends up on the same (soca) circuit on every breakout? Might it have been that way for years and slowly spread the damage with show changes?

 

[STEVETERRY]

Still interested in the pin #9 issue. If the cables are not swapped around much, is there a particular unit or type of unit that ends up on the same (soca) circuit on every breakout? Might it have been that way for years and slowly spread the damage with show changes?

And a corollary question: Why isn't the corresponding neutral pin of that circuit also burned?

ST

 

[JD]

Looking at the picture in the first post (blown up), I now see a white haze on the connector shell in that area on at least two of them. You may want to look at the male cable ends. It could be that the plate is not perfectly level and water is somehow seeping in and pooling inside the front of the male connector on that side. Since the two adjacent pins are neutral, and therefore close to ground potential, all of the corrosion would happen at the hot pin, #9. The dead giveaway would be residue in the male end between pin #9 and the shell.