What is possibility the motor current is not equal? Have a high discrepancy between phase >20 ampere.

1. After Replacement MS 2406 with
new motor

2. History:
• MS 2406 is 225 kW, I FL : 423 amp, 400 V, 4 poles,
50 Hz
• Replacement MS2406 with new motor on 31
January 2017
• Replace Power cable between MCCB to Busbar
Line (before size 3x1x120 mm2 to 3x2x120mm2)
on 1st February 2017
• Replace Contactor with new one on 8 February
2017
• Measure resistance of power cable (6 cores) from
motor terminal to Contactor terminal output,
result : all are good (0.278Ω)

3. • Tightening all bolt and nut at terminal.
• Solo run new motor without pulley on 31
January 2017. Result :
• R phase = 201.8 Ampere
• S phase = 202.4 Ampere
• T phase = 199.3 Ampere
• On 7 February 2017, took current of motor.
Result:
• R phase = 365.4 Ampere
• S phase = 360.1 Ampere
• T phase = 386.8 Ampere

4. • On 8 February 2017, took current and voltage. Result:
• R phase = 382 Ampere
• S phase = 380 ampere
• T phase = 403 Ampere
• R-S = 389 Volt
• S-T = 390.1 Volt
• R-T = 392 Volt
• On 13 February 2017, took current and result:
• R phase = 406 Ampere
• S phase = 398 Ampere
• T phase = 428 Ampere
• On 24 February 2017, took current 2 times,
• R phase = 416 ampere
• S phase = 392 ampere On 13:30
• T phase = 400 ampere
• R phase = 403 ampere
• S phase = 379 ampere On13:40, adjust the underflow
• T phase = 386 ampere valve

5. • On 26 February 2017, took current and result:
• R phase = 419 Ampere
• S phase = 394 ampere
• T phase = 405 ampere

6. Power cable resistance and new cable
(3x120mm2 change to 3x2x120mm2)

7. Solo run motor on 31 January 2017

8. Current on 7 Feb.2017 (left) and 8 Feb.
2017 (right)

9. Current on 13 Feb.2017

10. Current on 24 February 2017
Took current on 13:30
Took current on 13:40 after
adjustment the Underflow valve

11. MS 4206 underflow valve
Underflow valve

12. MCCB
FILTER
INVERTER
3x240mm2
3x240mm2
NSC 630K
FILTER
CONTACTOR CONTACTOR
MS 2406
Motor
MS 2428
Motor
MCCB MCCB NSX 630N
Over Load
Relay
Over Load
Relay
2x(3x120mm2),
NEW REPLACEMENT
NSX 630N
NFI 600
NFI 600, 600 Amp
CONTACTOR
3x240mm2
NYY 2x(3x150mm2)
LC1D475 LC1D475
LC1D500,
NEW REPLACEMENT
LR9 F 7379 LR9 F 7379
AC REACTOR
SIMPLE FLOW POWER SEPARATOR SYSTEM
NOTE:
: BUSBAR
: NYY CABLE
: TERMINAL
CONTACTOR LC1D475
Cable resistance is 0.278 Ω
BUSBAR LINE 400 V
530 A, 0.013 mH
Class F

13. Summary:
• After replace with new motor, new power cable
and new contactor, and 6 times measurement of
motor current, the current of motor always
change, it is not high only one phase (before T
phase) but the other phase also (R or S phase)
• On 24 February 2017, 2 times measurement. 1st
condition is took on 13:30 and 2nd condition with
a little adjustment of Underflow valve on 13:40.
The current motor decrease while the valve little
bit open.

14. Table of Motor Current
Phase (ampere)
Date R S T
31 January 2017
(solo run)
201.8 202.4 199.3
7 February 2017 365.4 360.1 386.8
8 February 2017 382 380 403
13 February 2017 406 398 428
24 February 2017
(13:30)
416 392 400
24 February 2017
(13:40)
403 379 386
26 February 2017 419 394 405

15. • Question:
• Why the load/current between phase is not
equal? (have more 20 ampere)
• What is caused?