Multitech 1777.8/7-10 G3 Multitec, Vacuum balance line, 5.5Connection to power supply

Multitec

5.4.1 Vacuum balance line

Where liquid has to be pumped out of a vessel under vacuum, it is advisable to install a vacuum balance line. This line shall have a minimum nom. diameter of 25 mm and must extend above the highest permissible liquid level of the vessel.

An additional pipeline fitted with a shut-off valve – from the pump discharge nozzle to the balance line – facilitates venting of the pump before start-up.

A Main shut-off valve 1212:5

BVacuum balance line C Shut-off valve

E Vacuum-tight shut-off valve R Swing check valve

V Vessel under vacuum Z Intermediate flange

Fig. 11 Suction line and vacuum balance line

5.5Connection to power supply

Connection to the power supply must be effected by a

trained electrician only (see 5.1)!

The applicable DIN VDE regulations or country-specific guidelines must be complied with.

Check available mains voltage against the data on the motor rating plate and select appropriate start-up method.

All connections shall be effected in accordance with the technical specifications issued by the local energy supply company.

We strongly recommend to use a motor protection switch.

5.5.1 Connecting the motor

Connect the motor in accordance with the circuit diagram in the terminal box or as illustrated in fig. 12 or fig. 13.

Caution	Prior to starting the motor, check whether the wires
	are firmly connected at the terminals and
re-tighten any loose wires.
n configuration (low voltage)

Y configuration (high voltage)

1145:32/2

Fig. 13 Connection diagram for three-phase motors,

Yconfiguration

5.5.2Setting the time relay

Make sure that in the case of three-phase motors with star-delta starting method switching over from star to delta will be effected at very short intervals. Prolonged switchover intervals may result in pump damage.

Recommended time relay setting for star-delta starting: 3 to 5 seconds, depending on motor rating.

EN 50014 (DIN VDE 0170/0171 Part 1) stipulates that explosion-proof motors, type of protection IP 54, increased safety (Ex)e, thermal class T3, must always be connected via a motor protection switch.

5.5.3 Checking the direction of rotation

Caution	On pumps fitted with uni-directional mechanical
	seals (seal codes 62 and 63) the direction of
rotation must	never be checked with the pump coupled to the

motor. If the pump/motor coupling does not have to be removed, make sure that the pump has been primed before checking the direction of rotation.

The motor’s direction of rotation must correspond to the direction indicated by the arrow on the pump or motor (clockwise when seen from the motor end; on version D anti-clockwise). Verify by switching the motor on and then off again immediately.

If the pump runs in the wrong direction of rotation, interchange any two phases L1, L2 or L3 of the power cable in the motor terminal box.

1145:31/2

Fig. 12 Connection diagram for three-phase motors,

nconfiguration

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