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baldsparkies
Have been concerned about an install thats running on the warm side.
MCCB is rated at 200 250A supply cable is supposed to be 95mm swa (4 Core) which surprises me looks more like 70mm at best 50mm worst. Nothing on the side wall (Darn those manufacturers)
Now the MCCB has a design operating temp of 65 degrees and the tech dept as confirmed that table 4D4A not 4E4A should be used for cable sizing and current ratings.
The logic being that whilst 90 degree thermoplastic offers a higher design current Table 4D4A should be used to keep the temps within the design limits of the connected devices. Also with the MCCBs the max currents do drop off considerably as temps increase.
All this makes perfect sense, but my main concern is a supposed 95mm cable running hot to the touch when only pulling 170 amps per phase. If 95mm we should be looking at 304A with xlpe or 251A with the 70 degree.
Connections are all good so would you guys be of the same thoughts as me ie 95mm + 170 amps = cable running at close to ambient temp, not blimey thats getting warm WTFs going on here.
Thanks for your thoughts on this one my learned friends, always nice to have second opinions.
I deffo am going to try and get the cable sizing verified asap. Will be armed with a set of calipers and checking the outer diameter which i think should be around 41.7mm. if its a 95mm cable might check lug sizing as well
MCCB is rated at 200 250A supply cable is supposed to be 95mm swa (4 Core) which surprises me looks more like 70mm at best 50mm worst. Nothing on the side wall (Darn those manufacturers)
Now the MCCB has a design operating temp of 65 degrees and the tech dept as confirmed that table 4D4A not 4E4A should be used for cable sizing and current ratings.
The logic being that whilst 90 degree thermoplastic offers a higher design current Table 4D4A should be used to keep the temps within the design limits of the connected devices. Also with the MCCBs the max currents do drop off considerably as temps increase.
All this makes perfect sense, but my main concern is a supposed 95mm cable running hot to the touch when only pulling 170 amps per phase. If 95mm we should be looking at 304A with xlpe or 251A with the 70 degree.
Connections are all good so would you guys be of the same thoughts as me ie 95mm + 170 amps = cable running at close to ambient temp, not blimey thats getting warm WTFs going on here.
Thanks for your thoughts on this one my learned friends, always nice to have second opinions.
I deffo am going to try and get the cable sizing verified asap. Will be armed with a set of calipers and checking the outer diameter which i think should be around 41.7mm. if its a 95mm cable might check lug sizing as well
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