Alpha Technologies CFR 3000, CFR 3000RM - Manual (Page 30)

2 Installation 24
2.8 Transformer Output Load Sharing (Continued)
2.8.2.1: Measuring the Output Current
This uses a clip-on current probe (Figure 2.12 for 240 VAC, Figure 2.13 for 208 VAC and Fig-
ure 2.14 for 230 VAC).
For 120/208/240 VAC units the total current drawn from Winding 1 is the sum of the currents A,
B and C where:
• A is the total current drawn by all of the 120V loads connected to the receptacle.
• B is the total current drawn by all of the 240V loads connected to the receptacle.
• C is the total current drawn from the L1 side of the terminal block.
The total of these currents must not exceed the rated output current for the L1 winding.
For the L2 winding of the transformer, measure the currents at points B and D where:
• B is the total current drawn by all of the 240V loads connected to the receptacle.
• D is the total current drawn from the L2 side of the terminal block.
The total of these currents must not exceed the rated output current for the L2 winding.
Output
Terminal Block
L2
L1
N
Winding 2
Winding 1
240 VAC
120
VAC
120
VAC
D
C
120 VAC
Receptacle
A
240 VAC
Receptacle
B
Output Current 2
Output Current 1
Output Current L1
Figure 2.12
120/120/240 VAC Current Measurement Points
Output
Terminal Block
L2
L1
N
Winding 2
Winding 1
208 VAC
Not Used
120
VAC
D
C
120 VAC
Receptacle
A
208 VAC
Receptacle
B
Output Current 2
Output Current 1
Output Current L1
Figure 2.13
120/208 VAC Current Measurement Points