Blance load test : LUSENET : Elevator Problem Discussion : One Thread

Is a balance load test reguired by ANSI 17.1? If not ,why not? Thanks

-- richard fraser (, March 26, 2000


No such test is required as far as I know.

Accordingly, there is no definition of what it would entail.

Without such a description, the benefits or lack thereof are not apparent, so the "why not" part of your question becomes hard to address.

How do you define "balance load test"? Why do you feel it should be a part of the Code?

-- John Brannon (, March 26, 2000.

Thanks for your answer. The reason for my question is based on what I was told by an inspector. He said a defective brake on an unbalanced car, where the counterweight was 175 lbs over the 40-50% of the car,could cause the car to drift upward faster than if it was properly balanced. Someone trying to exit that car might get wedged,according to him.Because of this concern, he thinks it should be required by ANSI.

-- richard fraser (, March 26, 2000.

ANSI A17.1 requires the brake to be able to stop and hold a car loaded to 125% of rated load. Initial (Acceptance) and periodic (5 year) tests are required to demonstrate this ability.

Since this is a greater load than would occur even with a severely unbalaced car, there would seem to be no need to test the brake with balanced load.

If the unloaded car could be pulled through the brake by the counterweight, it would surely show up in normal operation.

This would indeed constitute a serious safety hazard and is probably one of the reasons for the 125% tests.

-- John Brannon (, March 27, 2000.

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