Answer / bhupinder

In the same way as we have to synchronise the same capacity
generators. Capacity of source doesnt matter , the only
thing is F , V and phase of all the sources should be same
at the time of synchronising.

Answer / srinivasan j

First we satisfy the three Conditions
1.Frequency
2.Voltage
3.Phase Sequence

Capacity is not the matter because we synchronizing 4 engines
at different capacity 1000KVA - 2No's
1100KVA, 1150KVA.

Answer / kj

First of all it is possible to have different size of
generators synchronized. If the condutions of voltage
frequency and phase angle is correct. The load sharing must
be set for a percentage load. This means all set will have
the same load (example 60% of max load on all sets).
Issues can be where the load sharing is not set correctly
or where the governor response is too different. This can
cause hunting of the load from one set to the others.
Another inportant consideration is the wave form. If it is
different high current can flow through the neutral. If the
alternators are made by the same company this is not an
issue.

Answer / sudhanva madhukar mahamuni

Dear All,

Kindly note that we cant / can synchronise DG sets of
different sizes. There are some major conditions which are
not allow to synch. differrent sizes of dg sets.

assume that 500kVA and 250kVA DG Set we have to syn.

if we loaded 80% on 500kva dg set + 50kva, then 250 will
start up and syn. with 500 kva but kindly note that it will
not share only 50 kva or both will not share the load
equally. and when load will get decrease then due to hunting
effect bigger size will share more load than lower one and
cascade tripping will take place.

Answer / pandiyarajan

We can synchronize if voltage, frequency & phase angle match.
Loading on different size DG set depend on the capacity & impedance value.

Answer / chat lang

yes im agree all your answer because we experience this
kind of problem we use 3nos of 500 and 1nos 1150kva this is
synchonized connection, then the 1150kva genset is shutdown
and he dont want to accept load sharing yes he start for
1hr but then shutdown he dont want to have load sharing in
other genset and on the ((DSE scada module)) telling or
indicating is no communication on main unit, then we
disconnect that ((1150kva genset. the spec of genset is
same like the 3nos 500kva pf 0.8 rpm 1500 HZ 50)) so what
was the posible cause of this problem,

Answer / sann hlaing

the best way is same capacity.

How will u calculate wire size according to current rating?

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