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Topic Title: Electrical fit-out requirements
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Created On: 02 September 2013 12:18 PM
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 02 September 2013 12:18 PM
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greghenderson17

Posts: 6
Joined: 26 August 2013

Hoping for some assistance with regards to scope of fit out for a retail unit.

The scope dictated that the we would design and install the infrastructure up to an isolator within each unit.

The fit out would be by others at a later date depending on when the fit out would happen, and install from the isolator to their DB and outwards.

One of the fit out clients asked us to detail what allowances were made for unit in terms of electrical supply -after confirming the load, cable size method of install factor etc. They then asked us to confirm the Zs allowances to the unit - our calculations run only to the isolator and we would normally not detail the criteria of the fit as this can change based on what is being installed.

However it has been asked how we can verify that our sub main cable sizes are correct if we did not allow a Zs factor, as such, to the unit. We don't anticipate they will have any problems but I was hoping someone had come across this and could clarify if an allowance should be made or if it should be covered under the fit-out design.

Any insight on this demarcation of scope would be appreciated.

-Greg

Edited: 02 September 2013 at 02:04 PM by greghenderson17
 02 September 2013 01:27 PM
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AJJewsbury

Posts: 11552
Joined: 13 August 2003

Zs might be OK as you'll presumably have a much larger protective device to work with than the downstream stuff. Voltage drop might be more challenging though - if for example you'd used 3% on the submain, they'd be snookered with their lighting ccts.

- Andy.
 02 September 2013 04:34 PM
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Parsley

Posts: 1034
Joined: 04 November 2004

If it's a commercial site the Zs at the isolator is going to be fairly low I would have thought if the submain has been probably designed.
If the transformer is onsite a higher allowable % of VD can be used.

What size is the supply to the unit and what was the Ze and the Zs at the isolator?

Regards
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