Bus Loading

The exercise would be elaborate and involves documentation of all the equipment connected to the bus, their respective power factor and type viz. linear or nonlinear.

What is the rating of the bus and what ampereage you are drawing at present. The continuous rated load should be segregated and diversity of the remaining must be brought out specifically.

Eventually, it is always advisable to take conservative approach as far as bus loading is concerned.

Kind regards,

consider 100% Continuous load+50% intermittent load+0% Standby load

j_kamal: what do you mean by "conservative approach" as far as bus loading is concerned

biswanath.das: do you mean the current amp draw of a running load or the fulload amps?...."consider 100% Continuous load+50% intermittent load+0% Standby load"

If the ampacity of the busway is equal to or less than the service entrance fuse or breaker, would that not prevent the busway from being overloaded? Seem to me the whole service would trip off if the total accumulated load exceeded the fuse protection level.

Perhaps the whole service entrance setup should be examined and a fuse co-ordination assessment be done.

As rightly pointed out by Mr. Biswanath Das consider 100 percent continuous load and 50 percent intermittent load. By conservative approach, I meant taking into account a larger factor of safety and accordingly derating the electrical system equipment including busbars, switchgear and cables.

Kind regards,

Alternatively you can go by the Incoming breaker rating, if loads are not final at the initial stage of project.

Since you do not know how to do this, you should get someone who knows how to do it. Trying ot learn electrical engineering by posting questions to this forum can lead to unsafe installations.

That's correct Mr Blitz. We should be careful while using ideas/suggestion etc. Some people may mislead. It is better to go for a professional consultancy service who also bears the responsibility on the system performance.

Compute it? Not on my clock, Junior. Ever hear of an Amprobe? Just measure the current on the supply to the bus with everything on, and derate by 50%. The result? No go-backs if it passes, or the sale of a new load center installation if it doesn't. Everybody's happy, everything works, the 1st time.

Since I am not an electrical engineer I have to rely on advise from the professionals.

Have an electrical contractor hook up an amprobe to give you a printed graph of all loads on the bus bar. The monitoring of the loading may have to be done over a full week or even two weeks to get a complete picture of real life use. Knowing what the peak loading is and when will be helpful. Ask them for loading restrictions on what the code is, and what industry standards are. Have a certified engineer do the math and make the connections. Cover your backside by having somebody who knows what they are doing, insured, show due diligence.

This is great advice. Thankyou all