GEA CAIRfricostar - CS Klimateknik

Electrical ConnectionGEA CAIRfricostarMotor protection with thermal contactThermal contacts are temperature-dependent switching elements that automaticallymonitor the winding temperature of a motor. Compared to thermal tripping devices andmotor circuit breakers, these devices provide more effective protection under the followingcircumstances when installed in the motor winding:– Insufficient cooling– Increased ambient temperature– Extreme speed reduction during control and regulation operations– Shutdown of the motor in the event of control voltage failure on the line side– Faulty contacts and cable breakages in the control circuit.A thermal contact opens when the permissible temperature of the winding is exceeded.This interrupts the control signal loop of a control unit, for example. The fan protectiondrops out and disconnects the motor from the mains.The motor protection is intrinsically safe.7.2.2 Connecting electric motorsSingle-speed electric motorswith direct on-line startingSingle-speed electric motorswith Y/Δ startingIn order for the unit to operate properly it is important to connect it with a right-handrotating field.• Check the rotating field if necessary with a rotating field meter.DAMAGE TO THE UNIT!Correct assignment of the phase sequence to the specified rotational direction mustbe checked before the motor is connected. If the wrong connection is made themotor/fan may be damaged.The terminals of AC motors are labelled in such a way that the alphabetical sequenceof the terminal designation U1, V1, W1 corresponds with the temporal sequence of thephases L1, L2, L3 (with clockwise rotation).The rotational direction can be reversed by exchanging two connecting cables:– Exchange the connecting cables, e.g. U1 and V1– Y connection: Exchange the connecting cables, e.g. U1 and V1– Δ connection: Exchange the connecting cables, e.g. U2 and V2Multi-speed electric motors: – Speed 1: Exchange the connecting cables, e.g. 1U and 1V– Speed 2: Exchange the connecting cables, e.g. 2U and 2VVoltage fluctuations • Make sure that the supply voltage with mains frequency is between 95 % and105 % of the rated voltage. Only then can the motors operate at their rated output,otherwise they may be damaged.To make the connection, proceed as follows:• Connect the unit according to the wiring diagrams.One speed motorOne speed 3-phase-motors with frequency converters for plug fansTwo speed motorTwo speed 3-phase-motors for belt-driven fans40 PR-2006-0019-GB • Subject to modifications • Status 05/2009