4761 Standard Current Transformer 1000A0 pages

4761
Current Comparator

The errors of conventional standard current
transformers inevitably depend on the burden. A
magnetic flux in the core produces the e.m.f. which
sustains the secondary current in the burden. This
disadvantage has now been eliminated by the
development of the two new current comparators,
types 4761 and 4764. An indicator winding measures
the magnetic flux in the core, while an amplifier - by
regulating the current in a compensating winding makes sure that the flux in the core is approximately
zero.

DESIGN
The housing of both comparators is made of a
insulating material. All terminals and controls are
mounted on the top panel.
The holes for the wires of the bushing transformer
are on the lateral face of the unit.
Type 4761 is portable.
Type 4764 is equipped with castors.

CURRENT RANGES
Secondary:
Primary:

1-5A
5 ... 500 A*
500 ... 5000 A**
* in 94 steps at the terminals.
**in 62 steps, produced by one and two
respectively.

wires,

The range of type 4764 can be extended up to 10 000 A
by means of the auxiliary transformer, type 4766 ( Higher
values on request).
K1:
K2:
K3:
A:
B:
C:
D:

1/3

Outside (hollow) annular core
Inside annular core
Auxiliary core
Secondary winding
Compensation winding
Indicator winding
Primary winding