M
markc17
Hi all,
I commissioned the renewal of some mains intake equipment at a building that involved a full shut down. The building runs 24/7 and so a shut down is a VERY rare event. Upon completion of the works the contractor informed me that the 95mm 4 core cable feeding the building was being protected by 200 amp fuses. I looked at table 4D4A and this suggests that the maximum currenct carrying capacity for a cable ot this type,running in ducting, is only 169 Amps.
I asked for old records and test results (which are sketchy at best) and it does seem to point at the fact that this was how the install was done from the outset. Periodic results from ten years ago conveniently have the cable size missed out on the results sheet. Unless i am missing something, this would mean i have to recommend they change their fuses to 160 amp ( which would be a virtual impossibility) or upsize the mains incoming cable which is going to be very costly. Before i recommend these works and upset the boat.. am i missing something?
I commissioned the renewal of some mains intake equipment at a building that involved a full shut down. The building runs 24/7 and so a shut down is a VERY rare event. Upon completion of the works the contractor informed me that the 95mm 4 core cable feeding the building was being protected by 200 amp fuses. I looked at table 4D4A and this suggests that the maximum currenct carrying capacity for a cable ot this type,running in ducting, is only 169 Amps.
I asked for old records and test results (which are sketchy at best) and it does seem to point at the fact that this was how the install was done from the outset. Periodic results from ten years ago conveniently have the cable size missed out on the results sheet. Unless i am missing something, this would mean i have to recommend they change their fuses to 160 amp ( which would be a virtual impossibility) or upsize the mains incoming cable which is going to be very costly. Before i recommend these works and upset the boat.. am i missing something?