Alimak Scando 650 DOL, Техническое описание

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ALIMAK 34736 - 1/01
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Power supply from generator set at jobsite
Required generator power
It is recommended that the generator is capable of providing a
starting current of A amperes at rated voltage. If this is not
possible, the guidelines below can be used.
For DOL starting of Alimak hoists having 1 or 2 drive motors
we suggest the following generator sizes:
– 1 motor drive size 132M, 13 kW (15 kW) 100 kVA min.
– 2 motor drive size 132M, 13 kW (15 kW) 200 kVA min.
It should be noted that the recommended generator sizes are
large due to the fact that the DOL starting of the motor(s) draws
a large current resulting in a voltage drop which would cause
the contactors to oscillate on and off. A smaller generator might
be used but this can only be established by practical experience
related to a specific make and model of the generator set.
For VFC (Variable Frequency Converter) operated hoists the
generator size in kVA should be approximately 2 x the installed
motor power in kW. (S3 = 25% ED).
Voltage drop in the power supply
Typical symptoms
– The hoist will not start with the full rated load.
– The brakes will not lift when starting in the Up-direction.
– The contactors oscillate on and off (”shatter”) when starting
with full load in the Up-direction.
– The contacts of the Up and the main contactors are damaged.
Steps to be taken to overcome a voltage drop problem
The best method to avoid any voltage drop problem is to make a
proper engineering review of the conditions at the job site
before installing the hoist. When installed, the options are
limited.
However, should a situation occur where the power supply seems
to be insufficient, it is important to determine whether this
depends on the voltage drop in the power supply or something
else. Use an instrument to measure the incoming power supply
voltage in both the B-panel at the base and the M-panel on/in
the car. Take the readings during starting conditions in the