Datasheet NW72 series, WQ72 series Specification

MOVING-IRON MEASURING
INSTRUMENTS

Application: Moving-iron measuring instruments mainly are used in power plants in order to measure

Meters:

- Magnetic screening from external fields:

Moving-iron measuring instruments are manufactured according to DIN EN 60 051 as well as

Design:

Accuracy: According to DIN EN 60 051 class 1,5, in special design

Test voltage: 2 kV
Own consumption: Voltmeters about 2 VA, ammeters 0,6 – 2 VA
System of protection: According to DIN EN 60 529
Front side IP 52, in special design IP 54
Terminals shock-proof, IP 10

alternating current and alternating voltage (direct measuring or by current resp. voltage
transformers).

Moving-iron measuring instruments will indicate the root mean square even in case of
distorted quantities within the frequency range of 15 up to 100 c.p.s. Regarding direct
current and direct voltage additional indication errors of about 1 % may arise due to any
faults of magnetization in the iron.

The own consumption of these measuring instruments is relatively high compared with
moving-coil measuring devices and is situated between 0,6 VA and 2 VA. Thus they are
unsuitable for measuring small currents or voltages such as at shunt resistors, impulse
transmitters, thermoelements, measuring transducers.

- Rugged and with high electrical overload capacity

- Spring-loaded toe bearing in sapphire stones

- Damping by silicon fluid bearing, response time about 1 sec.

- High torque

Voltmeters and ammeters up to 5 A 4 kA/m (type 72, 96, 144)
Ammeters higher than 5 A 2 kA/m (type 72, 96 144)
Type WQ 48 DIN 0,5 kA/m

to the further VDE and DIN directions concerned. The precision amounts to 1,5 % referred to
the final value of the measuring range. The dial graduation of ammeters in the normal
design possesses a twofold overload scale and begins at about 10 % (20 % in case of
voltmeters) of the final value of the measuring range. Moving-iron measuring instruments
can be overcharged 1,2-fold permanently, ammeters up to 50-fold for a short period and
voltmeters up to 2-fold. As for the rest DIN EN 60 051 will be applicable.

The connection will be effected by screws M 4 in case of voltmeters and ammeters up to 15
A, screws M 5 up to 60 A.

class 1

MÜLLER + ZIEGLER GmbH & Co. KG, Industriestr. 23, D-91710 Gunzenhausen

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http://www.mueller-ziegler.de ,e-mail: [e-mail]