Bus Stab Grease

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DAWGS

Senior Member
Location
Virginia
When doing MCC PM's and cleaning what do you guys do for re-greasing the bus stabs if needed? Do you purchase the manufacturers recommended grease? I would like to carry one brand for all manufacturers, but that wouldn't meet their recommendations. I have read that some people use mobile 28 grease on the stabs and connections. I priced out Square D's recommended lubricant and it cost $16 for a 2oz tube. I checked the MSDS and found the company that manufactures it for them and can get it for penny's on the dollar from them. These OEM company's really like to mark their "specialty" stuff up.
 

zog

Senior Member
Location
Charlotte, NC
Usually OEM recommended grease, you have to be careful mixing greases as they can chemically react when mixed and become hard as a rock, not a big deal for stabs but if used in an operating mech it can be a big deal. See the aftermath of that fairly often.
 

FionaZuppa

Senior Member
Location
AZ
Occupation
Part Time Electrician (semi retired, old) - EE retired.
--> MG Chemical Carbon Conductive Grease. good out to 200C.

DOW makes stuff (Molykote 111 is good)
MG Chemical makes stuff
Loctite makes stuff
SuperLube makes stuff

all used sparingly.
 

ATSman

ATSman
Location
San Francisco Bay Area
Occupation
Electrical Engineer/ Electrical Testing & Controls
Mobil SHC 32

Mobil SHC 32

https://www.amazon.com/Mobil-Mobiltemp-SHC-32-12-5/dp/B01M3Y732G

This is the synthetic red grease that GE recommends for the breaker finger cluster and stabs, mechanical parts, etc. Often they pack it in their LV & MV equipment before shipping. It is man made and does not seem to harden over time. Stay away from any petroleum based greases (white lithium, graphite, etc) which gets hard like glue when old (although they do bring us a lot of work :p)
 

big john

Senior Member
Location
Portland, ME
Mobilgrease 28. It's pretty much the industry standard all-purpose grease. Some OEMs specify it.

My personal opinion is that the conductive/non-conductive argument is a complete non-issue. Mobil 28 is actually a mechanical grease that I believe was designed for use in the aircraft industry, yet it still gets recommended by OEMs for contacts and stabs.

We routinely put it directly between flat mating surfaces and still have great low-resistance connections: I think as long as excess grease is allowed a path to escape so you're not building a hydraulic seal, it makes absolutely no difference because the grease itself is not a current carrying component. My guess is the high-points on the mating surfaces cut through the grease as long as it is fresh and pliable.

I would actually be very wary of using anything with solid metal "conductive" filler because it seems to me those could create a physical barrier between connections: It's anecdotal, but I've seen several destroyed groups of breaker fingers where somebody used copper anti-seize, probably thinking it would improve the connection. It didn't.

Use something that isn't super viscous but still won't drip everywhere at high temperature, and make sure you don't mix different lubricants. Other than that, I think it's pretty immaterial.
 
Does anyone use Kopr-Shield or similar for this application? It lists coating stranded wires before terminating on the bottle but I haven't used for that. Curious what results others have had?
 

kwired

Electron manager
Location
NE Nebraska
Does anyone use Kopr-Shield or similar for this application? It lists coating stranded wires before terminating on the bottle but I haven't used for that. Curious what results others have had?
My guess is that is a product with "conductive fillers" like Big John was talking about avoiding in switching contacts or spring tension clamping connections. It should be fine for connections with mechanical clamping, like a lug.
 

FionaZuppa

Senior Member
Location
AZ
Occupation
Part Time Electrician (semi retired, old) - EE retired.
big john had a concern using conductive greases. i found some online research and they found that the conductive powders used are really only useful when its a thin film and the conductors are clamped, otherwise there was no real benefit seen (except to kill off some arc flash). it was also written that having metal in the grease means knowing what corrosive area it could fall into due to dissimilar metals in the mix.

some other data also suggests that if using the construction "no-xx-ox" stuff it is meant to be buffed on, not smeared.

maybe some new testing is in order, i have a ~1000A+ variac setup to play with.
 

ramsy

Roger Ruhle dba NoFixNoPay
Location
LA basin, CA
Occupation
Service Electrician 2020 NEC
Never use grease unless factory applied to listed-equipment, or when Al wiring calls for NoAlox anti-oxidant compounds.

Where no factory lub exists, de-energized bus & meter stabs gets this electrical-grade lubricant. Cleans up equipment like a solvent with soft cloth. The long red straw, attached to side of can, helps with precision application to avoid waste.

CRC 2-26
d93e4073-6160-4be8-86fd-42e9b443b049_1000.jpg
 

FionaZuppa

Senior Member
Location
AZ
Occupation
Part Time Electrician (semi retired, old) - EE retired.
Never use grease unless factory applied to listed-equipment, or when Al wiring calls for NoAlox anti-oxidant compounds.
so the meter is on the side of a ocean-front home, both the stab box and meter come w/o grease. you would recommend no grease? and "no-xx-ox" isnt just for Al.
 

ramsy

Roger Ruhle dba NoFixNoPay
Location
LA basin, CA
Occupation
Service Electrician 2020 NEC
so the meter is on the side of a ocean-front home, both the stab box and meter come w/o grease. you would recommend no grease? and "no-xx-ox" isnt just for Al.

I didn't know anything survived marine environments for long, except perhaps stainless steal.
OEM listed Grease for equipment seems more durable than spray on lub for Marine areas, but don't know for sure.
 
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DAWGS

Senior Member
Location
Virginia
After some more research with my Siemens rep, it appears the contact grease part #15172791233 that Siemens sells for $77 per half pint can is actually just red mobile 28 grease. He sent me the MSDS sheet and its strait from mobile. Now I just have to get Cutler Hammer and GE grease specs and find their supplier for pennies on the dollar.
 
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