There is not enough information there.
It's clearly an ACB, and it looks like an old EE E3, which could be 3.3kV.
If he doesn't know how to operate any item of switchgear, he should be nowhere near it.
EE used the same or similar facia for most of their range, only really adding more information/options as they got higher in voltage, by the time you get to the E7 & E8 they do look significantly different to the lower voltage stuff.
This could be a 415V or 3.3kV ACB.
Edit.
If it is 415V it could be the M-pact range, likely in a form 4 switchboard, but there is no way to be sure from these photos.
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Thanks for your help, unfortunately there is no other information available.
He would not work on an item that he does not know how to operate, hence my asking for information - we're trying to find someone that has worked on these to assist - we've drawn a blank so far but hopefully your additional information may help, so thanks again.
It is pretty important you get the right information, English Electric made the OB3 in the 1950s - this MUST NOT BE OPERATED!
It was redesigned to be the M-pact in the 60s and EE got swallowed up by GEC in the late 60s, after this the M-pact became the GEC M-pact (now known as the mk 1) since then it's become the mk2, new M-pact, M-pact plus etc.
The ob3 and M-pact mk1 look similar when you just have the small view as your photo.
Hello Katie.
Tell your husband not to touch it. There is almost certainly high energy present (arc flash hazard); it should have been risk-assessed and labelled as such. If so, that means arc-rated PPE is essential to safely operate this circuit breaker. The lack of arc flash labelling and circuit designation labels leads me to think it has not been maintained. If the site owner does not know how to operate it, it may not have been functioned for an unknown period of time and may be unsafe. Call the DNO; they have all the right PPE to deal with it and will also be able to service and test it, which will be required. It then needs to go on a routine maintenance schedule and be risk-assessed for the potential arc flash hazard. And, usually, the lower the service voltage, the greater the arc flash hazard, so don't relax if it's found to be "only" 415 volts. Keep well away from it in the interim.
Regards,
Colin Jenkins.
A wise move. Thanks for reassuring us.
A key point here is that an ACB of this type, is not something that you just operate without forethought. Even if you are skilled and familiar with the equipment, the procedure used needs to take account of the local conditions, maintenance status or lack of it, load being interrupted, prospect of closing onto a fault etc, all of which would be built into the risk assessment for the activity.
These things can be deceptive. They sit quietly for decades giving an impression of solid reliability, but without actually being called upon to perform their job and without the maintenance necessary to keep them ready to spring into action. Then, when someone finally presses the button and the neglected mechanism malfunctions, it erupts into a fireball.
A key point here is that an ACB of this type, is not something that you just operate without forethought. Even if you are skilled and familiar with the equipment, the procedure used needs to take account of the local conditions, maintenance status or lack of it, load being interrupted, prospect of closing onto a fault etc, all of which would be built into the risk assessment for the activity.
These things can be deceptive. They sit quietly for decades giving an impression of solid reliability, but without actually being called upon to perform their job and without the maintenance necessary to keep them ready to spring into action. Then, when someone finally presses the button and the neglected mechanism malfunctions, it erupts into a fireball.
If it is an OB3 it would be dependent manual operation.
Which means it closes as slowly as you operate it!
People have been known to start opening them, halfway through closing them because they hear arcing.
It does indeed turn into a fireball.
M-pact and the E series could be independent manual, manual charged spring, motor charged spring, or solenoid.
To give a small example, this is a test where I applied a small fault to a piece of switchgear with a minor manufacturing fault (deliberate), the piece of heat sensitive board to the front-left of the switchgear is the size and in the place where the operator would be when operating it.
Unfortunately although you can see the "operator" pushed back, the angle obscures the view - the material was burnt right through in places, indicating the operator could have suffered 3rd/4th degree burns to 75/40% of their body.
Unfortunately although you can see the "operator" pushed back, the angle obscures the view - the material was burnt right through in places, indicating the operator could have suffered 3rd/4th degree burns to 75/40% of their body.
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Vortigern
Arms
What are those disc things all around the room. In fact, what is that room? @Julie. And, errr, I have made a solemn promise to myself to not operate an air circuit breaker anytime soon!
P.S. And why must the OB3 NOT BE OPERATED? Is/was it defective like the above? All very interesting by the way.
P.S. And why must the OB3 NOT BE OPERATED? Is/was it defective like the above? All very interesting by the way.
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