Reduced Voltage Autotransformer Starters
Reduced voltage starters shall be Siemens Type SAT for motors up to 900 HP, 600V. Starter shall be the closed tran- sition type providing field adjustable volt- age taps for 50, 65, and 80% of the line voltage. The autotransformer shall be a NEMA medium duty with internal thermal protectors for protection of overheating due to excessive repeat starts that exceed the allowable number of starts on the transformer. Incomplete sequence protection is to be provided on all NEMA size 6–8 starters.
Autotransformer starters shall be equipped with three-pole double-break contactors with an arc quenching system consisting of arc chutes with arc splitter plates and a maximum 2 millisecond bounce time on sizes 2–5 to extend con- tact life. Run contactor shall be capable of carrying a minimum of 840% full-load cur- rent for 10 seconds duration on sizes 2–5. Starter shall include two three-pole con- tactors, to connect the autotransformer for reduced voltage starting, and a two- pole (run) contactor to bypass the auto- transformer and connect the motor for full voltage across-the-line running after a predetermined starting time is reached. A transition timer shall be provided which can be field adjusted to set the starting time. Starters shall be equipped with three-pole overload relays. Overload relay shall be a block type NEMA Class 10 with push to test feature, phase unbalance and phase loss protection, be field adjustable, and have an isolated alarm circuit contact. For NEMA Size 6–8 starters, the overload relay shall be a 3UB solid state micro- processor controlled device and have a field adjustable class setting from Class 10 through Class 30 to compensate for long accelerating times.
The starters shall be built and tested in accordance with the latest NEMA standard ICS 2-321 and UL Listed.
Multi-Speed Starters
Type S1, S2 multi-speed starters shall be equipped with three-pole, double-break contactors with an arc quenching system consisting of arc chutes with arc splitter plates, and a maximum 2-millisecond bounce time on sizes 2–5 to extend contact life.
Starters shall be equipped with three-pole overload relays. Overload relay shall be a block type NEMA Class 10 with push-to- test feature, phase unbalance and phase loss protection, be field adjustable, and have an isolated alarm circuit contact. For NEMA Size 6–8 starters, the overload
relay shall be a 3UB solid state micro- processor-controlled device and have a field adjustable class setting from Class 10 through Class 30 to compensate for long accelerating times. The starters shall be built and tested in accordance with the latest NEMA standard ICS 2-321 and UL Listed.
Reduced Voltage Wye
Delta Starters
Wye Delta Open And Closed
Transition Starters
Wye delta starters shall be equipped with three-pole double-break contactors with an arc quenching system consisting of arc chutes with arc splitter plates and a maxi- mum 2-millisecond bounce time on sizes 2–5 to extend contact life. Starter shall include three 3-pole contactors sized per NEMA standard ICS-2-321-7 and appropri- ate mechanical interlock.
A transition timer shall be provided which can be field adjusted to set the starting time. A fourth contactor will be used on closed transition starters with transition resistors wired in each phase. An incom- plete sequence relay shall be included to protect the transition resistors in the event the transition is not completed. Wye delta starters shall be equipped with a three-pole overload relay wired in the phase windings.
Overload relay shall be a block type NEMA Class 10 with push to test feature, phase unbalance and phase loss protec- tion, be field adjustable, and have an iso- lated alarm circuit contact. For NEMA size 6–8 starters, the overload relay shall be a 3UB solid state microprocessor controlled device and have a field adjustable class setting from Class 10 through Class 30 to compensate for long accelerating times. The starters shall be built and tested in accordance with the latest NEMA Standard ICS 2-321 and UL Listed.
Reduced Voltage, Part
Winding Starters
Part Winding Starters
Part winding starters shall be equipped with three pole double break contactors with an arc quenching system consisting of arc chutes with arc splitter plates and a maximum 2-millisecond bounce time on sizes 2–5 to extend contact life. Starter shall include two three-pole contactors mechanically interlocked. A transition timer shall be provided which can be field adjust- ed to set the starting time. Starters shall be equipped with three-pole overload relays. Overload relays shall be a block type NEMA Class 10 with push-to-test
feature, phase unbalance and phase loss protection, be field adjustable, and have an isolated alarm circuit contact. For NEMA size 6–8 starters, the overload relay shall be a 3UB solid state microprocessor con- trolled device and have a field adjustable class setting from Class 10 through Class 30 to compensate for long accelerating times. The starters shall be built and test- ed in accordance with the latest NEMA Standard ICS 2-321 and UL Listed.
Solid State Reduced Voltage Starters Voltage Limit: To set a soft start, no need to know full load amps regardless of motor size (it limits inrush current dur- ing the starting period). It reduces peak torques at near synchronous speed com- pared to current limit start.
Impulse Start: Provides breakaway torque for high friction loads such as crushers or mixers, it reduces motor heating compared to ramp starts.
Shunt Trip: For positive isolation on fault conditions; in case of 2 shorted SCR’S. Emergency Start: With a shorted SCR, controller should be able to soft start and run to save the process.
Under / Over Voltage: Under over volt- age protection prevents motor and con- troller damage.
UL Ratings: UL Listed and short circuit tested for 65 kA or higher with circuit breakers (magnetic trip only breakers). Short circuit tested for 100 kA with RK5 fuses.
Diagnostics: On board fault diagnostics with selectable fault relay output. Initialization Check: 50-millisecond check on start; for short circuit, power line conditions, and load connections.
Re-Start of Rotating Motors (Start on the Fly): Starting motors with applied BEMF (back electro magnetic force) with no transients. No need to wait for field to collapse or decay. Smooth reversing. Power Outage: Ride-through power out- ages for 0.5 seconds on control power up to 5 seconds on primary power.
SCR Thermal Protection: Temperature and current predicting model to protect SCR’s for all conditions by keeping semi- conductors below the rated junction temperature.
Fully Isolated Electronics: All inputs, relays and DC power components must be isolated from customer connections to provide noise immunity, 2500 volt di- electric with start.
Inputs: All inputs must operate on 120 volts including remote reset input. Communications: Communications port must be provided on the electronics to interface with IBM compatible PC via RS232 link.
