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I'm guessing this is one for the older chaps....
Got a job we are involved with at the moment, switchgear upgrades in a school built in '71. The submain between one end and the other is 4no single core 50mm pyros in a duct.
Original panel has been correctly slotted between the gland holes, however the locknuts used on the glands are the standard galv steel type thats magnetic so not really right (though its been wrong for 50 years). Ideally want to change them to brass. The glands were ID'd as 1H50 on the side, had a bit of googling found it was going to be 25mm and forseeing this issue ordered M25 brass locknuts.
The guy came to put them on, and they looked like it would fit, but they got almost onto the gland but they were just a tiny bit too small to start threading on, the original nuts go on fine. Now I'd generally at this point suspect that they are imperial sized and probably 1" BSW....but...... an imperial thread on a gland intended for a metric sized cable, could that even be a thing?
I get at in '71 the metric changever was happening, there are some 4 core MICCs in the same panel that are imperial sized, and thers even a ring that leaves board as 2.5/1 and returns as 7-029/3-036 but both systems on the same gland... I'm doubtful, buyt what else could it be.
If it is, where does one get 1" BSW brass locknuts from, the wholesaler I use for 'tricky' stuff quoted me a 4week lead time and 40 locknut minimum (its the lead time thats the killer). googing brings up plumbing fittings, but if I think BSP is different to BSW, with the sizing being to the internal bore of the pipe its intended to be used with, rather than the size of the thread
Got a job we are involved with at the moment, switchgear upgrades in a school built in '71. The submain between one end and the other is 4no single core 50mm pyros in a duct.
Original panel has been correctly slotted between the gland holes, however the locknuts used on the glands are the standard galv steel type thats magnetic so not really right (though its been wrong for 50 years). Ideally want to change them to brass. The glands were ID'd as 1H50 on the side, had a bit of googling found it was going to be 25mm and forseeing this issue ordered M25 brass locknuts.
The guy came to put them on, and they looked like it would fit, but they got almost onto the gland but they were just a tiny bit too small to start threading on, the original nuts go on fine. Now I'd generally at this point suspect that they are imperial sized and probably 1" BSW....but...... an imperial thread on a gland intended for a metric sized cable, could that even be a thing?
I get at in '71 the metric changever was happening, there are some 4 core MICCs in the same panel that are imperial sized, and thers even a ring that leaves board as 2.5/1 and returns as 7-029/3-036 but both systems on the same gland... I'm doubtful, buyt what else could it be.
If it is, where does one get 1" BSW brass locknuts from, the wholesaler I use for 'tricky' stuff quoted me a 4week lead time and 40 locknut minimum (its the lead time thats the killer). googing brings up plumbing fittings, but if I think BSP is different to BSW, with the sizing being to the internal bore of the pipe its intended to be used with, rather than the size of the thread