
5.POWER SUPPLY FANUC AC SERVO AMPLIFIER β series B-65232EN/03
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5.3.2 How to Select a Transformer
Select a transformer according to the load condition and the model of
the motor for which the transformer is used. Each transformer has
secondary winding taps for three amplifiers so that it can be
connected to two or three amplifiers.
For a machine with typical operating conditions, select a transformer
according to the following guideline.
(Sum of three-phase power requirements of all models) × 0.6 ≤ transformer rating
Table 5.2.1 Table 5.3.1
CAUTION
When two or more motors are used, the
transformer rating obtained using the above
expression may be less than the actual power
requirements of any one of those motors. Should
this occur, use the motors’ maximum power
requirements as the transformer rating.
(Example)
The power requirements of the α22/3000i and
α2/5000i are indicated in Table 5.2.1, as shown
below :
α22/3000i : 6.2 kVA
α2/5000i : 1.2 kVA
Using the expression given above, the transformer
rating is calculated as follows :
(6.2 + 1.2) × 0.6 = 4.4 kVA
The power requirement of the α22/3000i is 6.2
kVA, this being greater than the calculated
transformer rating of 4.4 kVA. So, the transformer
rating should be 6.2 kVA.