AC Controls
Guide Form Specifications
Specifications
15
AC Controls
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
Autotransformer starters shall be equipped with
The starters shall be built and tested in accordance with the latest NEMA standard ICS
Multi-Speed Starters
Type S1, S2
Starters shall be equipped with
relay shall be a 3UB solid state micro-
Reduced Voltage Wye
Delta Starters
Wye Delta Open And Closed
Transition Starters
Wye delta starters shall be equipped with
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
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
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
feature, phase unbalance and phase loss protection, be field adjustable, and have an isolated alarm circuit contact. For NEMA size
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:
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.
312 | Siemens Electrical Products and Systems | CSI Section 16160 | |
Specification Guide | |||
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