Checking the 3-phase connection for correct rotation
The electric hoisting motor on the hull unit requires 3-phase AC power for operation. The Motor Control Unit is equipped with a Phase Watch Relay (K303). This relay prevents operation of the hoisting motor if the 3-phase AC power connections are wrong with respect to the motor's rotational direction.
Prerequisites
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•  The CS90 is turned off.
•  The circuit breaker for the 3-phase AC power is closed. AC power is connected.
You must be equipped with a standard set of tools. This tool set must comprise the normal tools for electronic and electromechanical tasks. This includes different screwdriver types, pliers, spanners, a cable stripper, a soldering iron, etc. Each tool must be provided in various sizes. We recommend that all tools are demagnetized to protect your equipment.
Context
The Phase Watch Relay K303 is located at the right side of the Motor Control Unit. LED L1 indicates that the Phase Watch Relay K303 is activated. This mean that the 3-phase voltage is applied, and that the three phases are correctly connected with regard to the rotation direction of the hoisting motor.
WARNING
High voltages are used. This equipment must be serviced only by qualified personnel familiar with high-voltage equipment and the potential hazards involved. Failure to observe this precaution could result in bodily injury.
Procedure
1 Locate Hoist/Lower Switch (S302). Set the switch to position STOP.
2 Locate the Motor Protecting Switch (S301). Press the operating handle upwards to position ON.
3 Verify that LED L1 on the front of the Phase Watch Relay (K303) is lit.
4 If the LED is not lit:
a To disconnect power, disengage the circuit breaker for the 3-phase AC voltage.
b Locate terminal block E301 at the bottom of the Motor Control Unit.
c Reverse two of the three 3-phase cable connections.
d To apply power, close the circuit breaker for the 3-phase AC voltage.
e Verify that LED L1 on the front of the Phase Watch Relay (K303) is lit.
5 Locate the Motor Protecting Switch (S301). Press the operating handle down to position OFF.
Result
Requirements Results
The 3-phase AC power cable has been correctly connected to terminal block E301.  
The AC power connections are correct with respect to the motor's rotational direction.  
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