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C.1 capacity formulas – Delta Electronics Elevator Drive VFD-VL User Manual

Page 245

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Appendix C How to Select the Right AC Motor Drive|

C-2

Revision Nov. 2008, VLE1, SW V1.03

C.1 Capacity Formulas

1. When one AC motor drive operates one motor

The starting capacity should be less than 1.5x rated capacity of AC motor drive
The starting capacity=

)

(

_

_

_

_

_

5

.

1

375

cos

973

2

kVA

drive

motor

AC

of

capacity

the

t

N

GD

T

N

k

A

L

Ч

⎟⎟

⎜⎜

Ч

+

Ч

Ч

Ч

ϕ

η

2. When one AC motor drive operates more than one motor

2.1 The starting capacity should be less than the rated capacity of AC motor drive

„ Acceleration time ≦60 seconds

The starting capacity=

(

)

[

]

(

)

)

(

_

_

_

_

_

5

.

1

1

cos

1

1

1

kVA

drive

motor

AC

of

capacity

the

k

n

n

P

k

n

n

N

k

s

C

s

s

T

s

T

Ч

+

=

+

Ч

Ч

ϕ

η

„ Acceleration time ≧60 seconds

The starting capacity=

(

)

[

]

(

)

)

(

_

_

_

_

_

1

cos

1

1

1

kVA

drive

motor

AC

of

capacity

the

k

n

n

P

k

n

n

N

k

s

C

s

s

T

s

T

+

=

+

Ч

Ч

ϕ

η

2.2 The current should be less than the rated current of AC motor drive(A)

„ Acceleration time ≦60 seconds

)

(

_

_

_

_

_

_

5

.

1

1

1

A

drive

motor

AC

of

current

rated

the

k

n

n

I

n

S

M

T

S

T

×

+

+

„ Acceleration time ≧60 seconds

)

(

_

_

_

_

_

_

1

1

A

drive

motor

AC

of

current

rated

the

k

n

n

I

n

S

M

T

S

T

+

+