~ 21 ~
NOVATEK-ELECTRO UBZ-305
Table 2.8
– Characteristics of UBZ inputs designed to connect CT
Current of UBZ inputs
designed for
measurement of CT
output currents, A
Ratio of overload relative
to rated current (5A)
Maximum duration of
current action, s
Minimum delay before
restarting, s
0
– 12
2,4
continuously
-
12
– 15
3
60
10
16
– 20
4
30
15
21
– 25
5
15
30
ATTENTION: MAXIMUM CURRENT OF UBZ INPUTS DESIGNED FOR MEASUREMENT OF CT OUTPUT
CURRENTS IS 25 A.
Rated input current of CT should be within the range: In<Ict<3*In.
It is recommended to use CT with Ict=2*In.
3 UBZ DESIGN
UBZ is microprocessor-based digital device that provides a high degree of reliability and accuracy.
Operational power is not required. The controlled voltage is simultaneously the power supply voltage.
4 SAFETY PRECAUTIONS
During operation and maintenance it is necessary to comply with the requirements of regulatory
documents:
Regulations for Operation of Consumer Electrical Installations;
Safety Rules for Operation of Customer Electrical Installations;
Occupational Health and Safety during Electrical Installations Operation;
TO ENSURE SAFE OPERATION OF THE PRODUCT IT IS STRICTLY FORBIDDEN:
–
TO CARRY OUT INSTALLATION WORKS AND MAINTENANCE
WITHOUT SWITCHING THE UNIT
OF POWER SUPPLY;
–
TO OPEN AND REPAIR THE UNIT INDEPENDENTLY;
–
TO OPERATE THE UNIT WITH MECHANICAL DAMAGES OF THE HOUSING;
–
TO PENETRATE MOISTURE ON CONTACTS OF TERMINAL BLOCKS AND THE INTERNAL
ELEMENTS OF THE UNIT.
5 INTENDED USE
5.1 SAFETY PRECAUTIONS
TO ENSURE SAFE OPERATION OF THE PRODUCT IT IS STRICTLY FORBIDDEN:
–
TO CARRY OUT INSTALLATION WORKS WITHOUT SWITCHING THE UNIT OF POWER SUPPLY;
–
TO OPERATE THE UNIT WITH MECHANICAL DAMAGES OF THE HOUSING;
–
TO PENETRATE MOISTURE ON CONTACTS OF TERMINAL BLOCKS AND THE INTERNAL
ELEMENTS OF THE UNIT.
5.2 UBZ Preparation for Use
ATTENTION: To improve performance properties of UBZ, it is recommended to install fuses (fusible
elements or their analogues) in the following circuits (listed in the order required; a hyphen is the
recommended fuse value):
1) UBZ power supply circuits (27, 28, 30
– L1, L2, L3) – 1 A;
2) circuits for measurement of temperature, current, voltage (39, 40, 44, 45, 48-52)
– 0.5 A;
3) RS-485 (33 - 35)
– 0.5 A;
4) relay output contacts (the fuse rating is selected according to the connected circuits, but it should not
exceed for contacts 1-3
– 15 A, for contacts 4-9 – 5 A).
5.2.1
Connect the current transformers in accordance with Fig.5.2;
5.2.2
Pass through a differential current transformer (zero sequence transformer) all three phase wires and
connect it to UBZ;
5.2.3
To monitor and measure the motor insulation, connect the control terminal of the insulation
25
to one
of output contacts of MS. If the motor housing is not grounded, or network with isolated neutral is used, or