Vanguard MCCB-250 User Manual download pdf (Page 16)

MCCB-250 USER’S MANUAL REV 2

Follow the steps below to measure the CT primary and secondary currents:

a. Connect the Safety Ground to the MCCB-250.

b. Connect the Current cables from the MCCB-250 to the bus (CT primary) as shown in

Figure 4.

c. Connect the CT secondary winding to the MCCB-250 [EXT CURRENT] input as shown

in Figure 4.

d. Turn the [CURRENT CONTROL] knob to zero.

e. Turn on the [POWER SWITCH].

f. Hold the [DOWN ARROW] key to momentarily turn on the current source.

g. Turn the [CURRENT CONTROL] knob to set the desired current.

h. Release the [DOWN ARROW] key.

i. Press the [UP ARROW] key to select the ON+TIMER mode and to start the test.

j. Observe and record the CT primary and secondary current and the polarity displayed on

the LCD screen. A typical LCD screen display is shown below:

NOTE

The external current polarity is shown as in phase (“+” sign) or out of phase

(“-”) with respect to the MCCB-250 drive current. The CT turns ratio can be

obtained by taking the current ratio.

k. Turn off the current source by pressing the [DOWN ARROW] key.

986 mS 59.2CY

Ext I:-1.004 A

Drv I:20.00A

1 2 ... 11 12 13 14 15 16 17

No comments

Vanguard MCCB-250 User Manual Page 16