Hi all,
We currently have a requirement to investigate replacing our existing Jeumont Schneider reverse acting AVRs.
The existing alternator is an indirectly self excited machine. The stator part of the generator excitation system comprises a differential compound winding arrangement (a shunt...
Hi All,
I need some help in troubleshooting an unexplained tripping of an MCCB. This breaker is installed in the main distribution board on an 440V, 60Hz, 3 ph, 3 wire system.
The breaker is a cutler hammer (eaton) AQB-L250 type breaker with a 175A plug. The instantaneous trip setting is Lo...
Hi all,
I need some assistance with some investigation into a dahlander motor winding failure. The motor drives an axial fan via a direct coupling. Based on anecdotal reports the fault appears to be occurring in the following scenario:
1. The fan is operating in high speed;
2. The fan is then...
Hi All,
I am currently involved in a new switchboard build project. We are currently having a new MCC manufactured for installation on a ship. The switchboard is to be integrated into a 440V system.
The new switchboard is to be fitted with MCCBs fitted within integral overcurrent protection...
I am currently reviewing a design of a new Motor Control Centre, fitted with a number of motor starters, of which a number are fitted with Siemens soft starters.
In the original requirements specification there was a requirement that all motor starter assemblies were type 2 coordinated...
Have recently come across a generator with both under frequency and Underspeed protection. Both the under frequency and underspeed protection relays were connected to the generator ACB trip circuit. However the Underspeed relay was also connected to the "de-excitation" circuit. Once the speed of...
Hi,
I have been recently made aware of an issue regarding erratic operation of a diesel alternator governor (or so it was reported) on a shipborne diesel alternator, part of a plant of three (3) 480kW DAs. The defect notice indicated that one of the DAs was load sharing eratically, continuing...
I have a question regarding the suitability of deep cycle lead acid batteries for use in a standby power application.
Recently, a contractor has replaced a NiCad (vented sintered plate construction) 80Ah, 24Vdc battery bank (made up of 20 cells) , with 2 off Supercharge 12V, 80Ah (Model No...
