changing from 400hz to 50hz 1

[ah1989]

dear friends
my company came across a diesel generating set, 100hp v6 duetz engine fitted to a german type 50kva, 400hz generator
they have a good workshop and they want to replace the generator by a 50hz, 93kva generator, is this possible any comments about speed , speed control, protection devices, etc...
all thoughts will be appreciated

 

[ccjersey]

You need to see what the engine is rated at 1500 rpm which most generators of that size turn to produce 50hz.

Even if it is rated 100hp at 1500rpm, it isn't powerful enough to deliver 93kw. If that is what you need, get a larger engine. If you only need around 50-60kw then the engine would be appropriate if it is rated 100hp at 1500rpm. Engines are usually sized to have roughly 1.7 hp/kW of generator capacity to give better response under sudden load increases.

The 93kVA generator end can still be used on the small engine if it will physically attach to the mounting flange etc.

Most speed governing and engine protection systems use an engine speed reference and battery charging system voltage, so the frequency change would not likely be a problem for the governor and engine controls. The governor will probably have to be set to get the correct speed (usually 1500 rpm).

 

[waross]

Hi ccjersey
ah1989 is asking KVA and your answering KW. If the engine is rated 100 Hp. at 1500 RPM it should be adequate for 93 KVA at 80% PF. If the 100 Hp rating is at a greater speed you will lose power dropping to 1500 RPM for 50 Hz.
The generators that I install are rated closer to 1.7 Hp/KVA.
What speed is the engine running now? You can usually adjust a governor for a wide speed range. 1500 RPM sets use the same governor as 1800 RPM sets. Some engines use a different governor for 3000 and 3600 RPM.
Engine controls should remain. You should purchase a new Automatic Voltage Regulator with Under Frequency Roll Off suitable for 50/60 Hz.
You will probably need a new main breaker.
yours