Peter Schaffel, managing director of motor control company, Ralspeed, has claimed that operators of temporary pump installations may be risking injury to personnel and damage to equipment if they use rented motor starters without first ensuring that these incorporate essential safety features such as earth leakage protection and effective short circuit protection.
“Almost by definition, pumps operate in damp areas,” said Schaffel, “so it’s the height of folly to use a starter that lacks earth leakage protection. In fact, if a serious accident occurred when such a starter was in use, it’s very likely that the absence of earth leakage protection would be seen as grounds for prosecution under health and safety regulations.”
Schaffel notes that this is not the only safety issue associated with rental starters. Because of their convenience and versatility, multi-motor starters, which are sometimes described as ‘one size fits all’ units, are becoming increasingly popular. They typically have a rotary switch that can be used to select motor overload protection for a wide range of motor sizes.
It is not, however, only the overload protection that needs to be matched to the motor size. Smaller motors are usually connected using smaller cables so, when using a multi-motor starter, it’s essential to confirm that the motor size setting also controls short circuit protection. If it doesn’t, these smaller cables will be inadequately protected, creating a risk of fire in the event of a short circuit.
“Yet another concern is starters that lack a main contactor,” added Schaffel. “Electronic soft starters are the ideal basis for rental units and, indeed, we use them in many of our own rental products. Nevertheless, it also essential to have a main contactor that will break the motor circuit instantly and positively if, for example, an emergency stop device is actuated. We firmly believe that safety is compromised by relying on the soft starter to stop the motor under such circumstances, then having to operate a manual isolator to positively break the circuit.”
