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SIEMENS VISIT 19 to 21 February 2008

Prepared by: A.ElSweesy

1st Day 19-2-2008 Events:

1- Discussing the problem of broken AFE circuit breakers & explained that this happens because the CUSA board is enabled before the charging process of circuit breaker motor is finished. In this case, electric pulses are generated to IGBTs which produces high harmonics to the charging motor causing it to continue rotating even after the stop point of spring has been reached. Mr. Rudolf (Siemens specialist) advised to add a hardware on-delay timer to delay enabling the CUSA board until the charging process is completed.

Attached wiring modification is shown below:

AFE Diagram =10 +E13A7A Page 9

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AFE Diagram =10 +E13A8 Page 14

2- Discussing the problem of damaged power clean filter capacitors & also K7 which passes power to them. Mr. Rudolf explained that this happens because of possibility of switching ON AFE circuit breaker immediately after it has been switched OFF & repeating this. In this case, Capacitors are not completely discharged after switching ON immediately which causes high current through capacitors & consequently damaging them. He advised to add a hardware off-delay timer to prevent switching ON immediately before certain time.

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Attached wiring modification is shown below:

AFE Diagram =10 +E13A7A Page 9

8age P6 A13E+10 =AFE Diagram

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3- Discussing the problem of MASTERGUARD UPS and the recommendation is to charge the batteries while they are outside the UPS because it must be some charge in batteries to be in a good performance in the UPS but we replied that all batteries in the store are fully charged and we replaced many but the problem still exists.

2nd Day 20-2-2008 Events: 1- Regarding the problem of MASTERGUARD UPS, Mr. Rudolf advised to check in other cranes if the input neutral to the UPS is earthed since it must not be earthed. We checked other UPSs which is working well and found the neutral is earthed. He will reply to us with corrective action!!!. 2- Regarding the problem of RRU2 auto-transformer overheating in CQ03, Mr. Rudolf advised to disable regeneration function as long as the crane is OFF and resuming when there is any command. 3- We measured the current to power clean filter capacitors of AFEs in CQ06 and found it around 1 amp. In all AFEs which have defected capacitors in power filter but the normal current is 73 amp. according to the datasheet. In power filters which have good capacitors the measured current is around 40 amp. and in some cranes around 70, 90 and 100 amp.. Mr. Rudolf said that the corresponding capacitors are not OK and may need to be changed but he will reply to us with corrective action.

4- Mr. Rudolf advised that UPS must be OK to maintain voltage stable and protect contactors from repeated switching ON and OFF and consequently damage power filter capacitors.

3rd Day 21-2-2008 Events:

1- Gathering data by NETWORK ANALYZER to view harmonics and variations in voltage and currents in AFEs of CQ06 and CQ11. Mr. Rudolf will reply to us with analysis results from factory of AFE.

Attached graphs shown below:

06in CQ variations currentAFE

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AFE voltage variations in CQ06

� Harmonics in CQ06

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11in CQVariations urrentsC

11 in CQ variations oltagesV

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11armonics in CQH

2- Reviewing Isometer setting of AFE1 in CQ06 and CQ11. Mr. Rudolf showed that its desired function is disabled. In our ZPMC cranes the main power neutral is not connected to ground (this system is called "IT system") as a safety from any short circuit will happen if any line voltage is grounded. 3- Collecting S/N of all ZPMC CQs AFEs and drives.

Conclusion:

1- Adding hardware on-delay timer to delay enabling the CUSA board until the charging process is completed to prevent AFE main CB damage, Siemens Advised.

2- Adding hardware off-delay timer to prevent switching ON immediately before certain time, preventing capacitors damage in AFEs, Siemens Advised.

3- CQ06 flashing UPS batteries indication lights problem still open (Waiting Siemens reply).

4- In Noell cranes, RRU regeneration function should be disabled when crane is off to protect feedback transformer from heating as siemens advised.

5- Defective capacitors in AFEs should be changed but waiting for Siemens Reply.

6- ZPMC should be inquired about the AFE isometer which is disabled – should it be enabled?

Ahmed El-Sweesy Electrical Engineer -Cranes Team Suez Canal Container Terminal 22-02-2008 15:00