By David Cooper - LECS

Please take this statement as my permission to photocopy this notice and to copy it to anybody who may be affected by it.

This safety notice is issued to colleagues in the industry following a recent investigation where we have identified a potential safety risk. In short, I am sure that you will agree that it is a reasonable assumption to make that when you take your fingers off the buttons of a car top control unit that the lift will stop. The investigation I have been involved with was into a situation where this did not occur and the lift continued to drive when the buttons on the car top control were released. Investigations revealed the reason to be a combination of circumstances. The lift was an old model and the car top control had been added as a modification long after installation. The lift engineer had placed a short on the safety circuit in the controller in order to locate a fault. As previously stated the lift was old and the control panel was similarly old. In this case the safety circuit left the controller from one electrical terminal and returned to another which meant that the short circuit was across the whole of the safety circuit. The engineer was unaware of this. Due to the age of the lift the car top control had been wired through the top and bottom floor pushes in the car, a method developed in the 1970's to save hanging a set of trailing flexes where the lift moves by shorting the safety circuit and placing an artificial call which is dropped when the car top control buttons are released. Because of the short circuit, when the car top control was operated, a top floor call was latched and the lift travelled upwards despite the engineer taking his fingers off the buttons, until the top floor stopping limit was broken. Given this scenario I would urge you to identify lifts wired in this manner and to take reactive action. If you require further information or clarification please do not hesitate to contact me as follows:

Office: 01323 431325
Mobile: 07710 608192
E Mail: davidcooper@lecs.co.uk