Starters & Enclosed Products
Reduced Voltage Starters
Controlled starting for low in-rush and smooth operation
Sprecher + Schuh reduced voltage starter, produced in our custom controls panel shop, are designed for starting squirrel cage induction motors where the starting current of a motor is likely to exceed local power company restrictions, interfere with plant operations or where the load may be damaged by high starting torques.
Starting with the best
All Sprecher + Schuh reduced voltage starters feature our CAT7 and CAT6 line of motor starters. These compact starters offer intermediate sizes to better match specific motor requirements. This equates to generous wiring space and less wasted horsepower capacity. Our advanced CEP7 solid state overload relays are used.
Choosing the right reduced voltage method
Autotransformer Starter — At starting, three autotransformers (one for each phase) are automatically connected in series with the motor. The voltage at the motor is reduced to either 50%, 65% or 80% depending on which voltage tap was selected. After a timed interval, a contactor connects the motor across-the-line and shorts out the autotransformers. Factory standard autotransformers are rated for “medium duty” as defined by NEMA.
Part Winding Starter — This type of starting requires that the motor winding be in two equal parts, and that at least six terminal leads be provided on the motor. At starting, the controller is arranged to connect one section of the winding to the supply lines. After a timed interval, a second contactor connects the other section of the motor winding to the supply lines, in parallel with the first.
Wye-Delta Starter — This type of starting requires a special wye-delta motor. Both ends of the motor’s three windings are brought out so they are accessible for reconnecting from wye to delta. At starting, the controller connects the motor in the wye configuration. After a timed interval, a second contactor connects the motor in a delta configuration.
International Standards and Approvals
Sprecher + Schuh's assembly department is an approved UL508 panel shop. We adhere to UL-mandated design and wiring standards. Our Canadian shop is also CSA-certified. Ask your representative for details.