Transformer output load sharing, Transformer output, Load sharing – Alpha Technologies CFR 3000, CFR 3000RM User Manual

Page 29: 8 transformer output load sharing, How to prevent the ups from being overloaded, Section 2.8), 60 hz units, 50 hz units

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23

2

Installation

2.8

Transformer Output Load Sharing

2.8.1: Transformer Output

The units have a single phase output. They do NOT have three phase characteristics.

Figure 2.10 shows the voltages between L1, L2 and N for 120/208/240 units and between L and
N for 230 VAC units

2.8.2: Load Sharing

The total current drawn from each winding must not exceed that winding’s maximum output
current rating (Figure 2.11). For 60 Hz units, where possible, connect 120 VAC loads to L1.

Since loads are shared between windings, you can exceed a winding’s output without exceed-
ing the unit’s maximum current output. There are two ways to calculate the current drawn by the
loads; measuring or displaying the output current.

z

H

0

6

0

0

0

3

R

F

C

z

H

0

6

0

0

0

3

R

F

C

z

H

0

6

0

0

0

3

R

F

C

z

H

0

6

0

0

0

3

R

F

C

z

H

0

6

0

0

0

3

R

F

C

z

H

0

5

0

0

0

3

R

F

C

z

H

0

5

0

0

0

3

R

F

C

z

H

0

5

0

0

0

3

R

F

C

z

H

0

5

0

0

0

3

R

F

C

z

H

0

5

0

0

0

3

R

F

C

1

L1

L1

L1

L1

L

s

p

m

A

0

.

5

2

s

p

m

A

0

.

5

2

s

p

m

A

0

.

5

2

s

p

m

A

0

.

5

2

s

p

m

A

0

.

5

2

L

L

L

L

L

s

p

m

A

0

.

3

1

s

p

m

A

0

.

3

1

s

p

m

A

0

.

3

1

s

p

m

A

0

.

3

1

s

p

m

A

0

.

3

1

2

L2

L2

L2

L2

L

s

p

m

A

4

.

4

1

s

p

m

A

4

.

4

1

s

p

m

A

4

.

4

1

s

p

m

A

4

.

4

1

s

p

m

A

4

.

4

1

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Figure 2.11

Transformer Output Current Ratings

230 VAC

120 VAC

120 or 88 VAC

208 VAC

240 VAC

L1

N

NEUTRAL

FERRO

TRANSFORMER

240 or 208 VAC

32 VAC

120 VAC

88 VAC

120 VAC

60 Hz Units

L

50 Hz Units

FERRO

TRANSFORMER

Figure 2.10

Transformer Output

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