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Post by Wheldale on Jan 14, 2013 13:18:58 GMT -5
Is the switch to turn coal face lighting or u/g workshop lighting on or off, is it a small switch that is intrinscally safe or are they like industrial button switches ie green on red off or are they something different? Sounds a bit daft but its something ive never seen or thought about really until i was day dreaming at work today!
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Post by John on Jan 14, 2013 13:45:42 GMT -5
Is the switch to turn coal face lighting or u/g workshop lighting on or off, is it a small switch that is intrinscally safe or are they like industrial button switches ie green on red off or are they something different? Sounds a bit daft but its something ive never seen or thought about really until i was day dreaming at work today! It's an FLP lighting transformer that has contactors and stop/start buttons on the front cover. Used to be a "size1 or 2 " Gate End Box enclosure. Face lighting used to be FLP light fittings with approved cables and plugs, they are now moving more to IS LED lighting.
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rac
Shotfirer.
Posts: 87
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Post by rac on Jan 14, 2013 13:59:26 GMT -5
i know of local lighting swithches housed in FLP enclosures with a lever on the front - either on or off ( the ones that spring to mind are/were Victor.) inside just a normal porcelain switch. what john refers to is the main feeds to several complete circuits with the above switches just used to isolate a few lights here and there rather than complete circuits.
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Post by Wheldale on Jan 14, 2013 13:59:27 GMT -5
Cheers John, never thought of an on/off switch on a transformer.
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Post by John on Jan 14, 2013 14:05:29 GMT -5
There were a couple of types of small transformers used in coal mining, a small free standing FLP unit that could be mounted on the rings, small but still bloody heavy!! It had capacity for a few lights as for example around a rope haulage installation. There was also a bus chamber mounted variant of that transformer too, to supply 110/240 volts for say powering up the AFC/Stage Loader console. That was later incorporated within the AFC/Stage Loader console which mounted on the GEB switchbank. Then the one I mentioned in my other post, large dual voltage transformer in a GEB enclosure with overloads/EL circuits and continuity circuits built in for each outgoing circuit.
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Post by dazbt on Jan 14, 2013 14:15:30 GMT -5
Then there was the Chinese face lighting method of course, (noticed this system when installing a new shearer by the way) where the lights were turned on or off by simply screwing the bulb in or out. A live twin wire run out along the face length with the occassional point where the insulation had been stripped off, one wire had strands parted and formed an 'O' into which the household type bulb was screwed until the base terminal of the bulb came into contact with the other bared strand, simples !!
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Post by John on Jan 14, 2013 14:23:10 GMT -5
Then there was the Chinese face lighting method of course, (noticed this system when installing a new shearer by the way) where the lights were turned on or off by simply screwing the bulb in or out. A live twin wire run out along the face length with the occassional point where the insulation had been stripped off, one wire had strands parted and formed an 'O' into which the household type bulb was screwed until the base terminal of the bulb came into contact with the other bared strand, simples !! Scary!!! I recall when face lighting was being introduced into collieries during the 60's. Most Elec Engineers refused to have anything to do with it on legal grounds. The M&Q Act rules introduced for face lighting stated every installation shall be removed every 30 days and taken to an approved workshop to be examined and tested. The approved workshop was the surface electric shop. Another rules was when shotfiring takes place, all face lighting circuits shall be isolated, and after the round of shots had been fired, all cables and lights within the are of the firing shall be examined before being energised. Then each seven days, an electrician was required to examine every cable, light fitting etc and sign the approved forms.... No wonder engineers refused to have it installed..
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Post by smshogun on Feb 8, 2014 15:40:10 GMT -5
Qualcast of Derby also did a standard range of FLP enclosures for multiple applications, many collieries used them for conveyor start/stop switches.
These came with a side lever for visual indication, bottom push/pull button, and even a keyed application switch with a triangular key so you could switch multiple applications, or have forward and reverse.
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