Non-magnetic materials in TFo and cable's clamp
Non-magnetic materials in TFo and cable's clamp
(OP)
I need the advise.We have dry-type 2500 kVA transformer(TFo)
10/0.4 with the envelope (IP31).The manufacturer made the
non-magnetic(but conducting) rectangular part of the envelope near the place of 10 kV cable lead-in ( something like aluminium or duralumin),the same for LV lead-in,but I speak about HV.We have 3 one-core screened 10 kV cable between a/m TFo and upstream RMU( Ring Main Unit) The manifacturer uses magnetic ( steel)clamps for fixing the cable in RMU.The clamp constitutes curcuit.
I can't understand why does the manufacturer prevent the heating due to magnetic reversal in TFo envelope and doesn't prevent it in RMU,using steel clamps.Is it correct to use magnetic material in one-core cable clamps made curcuit ?
Best regards
10/0.4 with the envelope (IP31).The manufacturer made the
non-magnetic(but conducting) rectangular part of the envelope near the place of 10 kV cable lead-in ( something like aluminium or duralumin),the same for LV lead-in,but I speak about HV.We have 3 one-core screened 10 kV cable between a/m TFo and upstream RMU( Ring Main Unit) The manifacturer uses magnetic ( steel)clamps for fixing the cable in RMU.The clamp constitutes curcuit.
I can't understand why does the manufacturer prevent the heating due to magnetic reversal in TFo envelope and doesn't prevent it in RMU,using steel clamps.Is it correct to use magnetic material in one-core cable clamps made curcuit ?
Best regards






RE: Non-magnetic materials in TFo and cable's clamp
RE: Non-magnetic materials in TFo and cable's clamp
insists on using non-magnetic clamps and bolts for fixing
the single core cable to the steel enclosure of 10 kV RMU whereas the manufacturer of RMU ( ring main unit)uses steel for these details. My question is :do any documents regulate this point ? ( the current approx.150A and the cable is screened - I think it's important)
RE: Non-magnetic materials in TFo and cable's clamp
RE: Non-magnetic materials in TFo and cable's clamp
"A single-conductor cable carrying a current over 200 A shall be run and supported in such a manner that the cable is not encircled by ferrous material."