Caution, Dmiiis – Amprobe DM-111S Current-Data-Logger User Manual

Page 45

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DMIIIS

EN - 43

11.3. USING THE INSTRUMENT IN A THREE PHASE 4 WIRE SYSTEM

CAUTION

The maximum voltage between L1, L2, L3 & COM inputs is CAT III 635 V~
phase

– phase 370 V~ phase to earth. Do not measure voltages exceeding

the limits prescribed by this manual. Should you exceed the voltage limits
you could damage the instrument and/or its components or endanger your
safety.

L

1

B

L

U

E

L

2

L

3

N

R

E

D

B

L

A

C

K

Y

E

L

L

O

W

Fig. 2: Instrument connection in a three-phase 4 wire system

CAUTION

If possible, before connecting the instrument to the electrical equipment to
be tested take the power supply off the electrical equipment.


1. Check, and if needed modify, the basic settings of the instrument (see paragraphs 5.2

and 5.3). Particularly, the 3PH4W mode must be set.

2. Rotate the switch to the position corresponding to the type of analysis desired. In case

of doubts, select the position POWER (see paragraph 6.3).

3. Connect the phase and neutral voltage wires following the connections shown in Fig. 2.
4. To measure current and power, connect the clamp meter to the phase conductor

following the specifications shown on the clamp and the connections shown in Fig. 2. In
case of doubts select the position POWER and, connecting one clamp a time, check if:
a) the phase sequence is correct (see paragraph 6.1.2).
b) the active power P of each phase is positive. If it is negative, remove current

transducer from the wire and reconnect it so the transducer label faces the opposite
direction.

c) the value of the Pf of each phase is not excessively low (typically it is not lower than

0.4). In case the Pf is lower than 0.4, check if the phase voltage is associated with
the right clamp meter, (for example the voltage of phase 1 must be associated to
the clamp meter no. 1).

5. Apply voltage to the electrical equipment under test (if previously shut off for the

instrument connection).

6. The values of the available electrical parameters will be displayed. For further details

see the paragraph relevant to the position of the switch.

7. You can press HOLD to interrupt the real time updating of the displayed values.
8. If you want to record:

a) Check and modify the values of the basic parameters (see paragraphs 5.2 and 5.3).
b) Check and, if needed, modify the recording parameters by pressing MENU (see the

paragraph corresponding to the position of the rotary switch selected).

c) To start the recording press START (see chapter 6).

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