standards and manufacturer practice 1

[144x]

A power cable manufacturer specifies that the distance between 2 rows of the cable trays to be X centimeter.the contractor in his erection documents specifies this distance to be Y centimeter where Y is about 50% less than X.when contractor was told that he should conform to the manufacturer's standard he said that he's following some specific standard and that cables are manufactured based on the same standard.
considering he's right in his comments what would be your answer to him?
thanx.

 

[jghrist]

I assume you mean spacing between cables in a cable tray. There may be industry standards for minimum spacing that are a requirement for ampacities stated in the standards. NEC 392.11 in the USA has such a requirement.

If this is a system that was engineered by the cable manufacturer, the manufacturer will have determined what spacing is required for the supplied cable. This spacing must be maintained.

My answer to the contractor would depend on what the contract requirements are. If the contract documents (specs and drawings) say he has to follow the manufacturer's spacing requirements, then he can be legally required to do so. If the contract doesn't say anything about this, you may only be able to require the contractor to meet industry standards. In this case, you will have to negotiate a change order and give him some extra money to comply with the manufacturer's design spacings.