BEQ - Bimetal Maximum and Moving Iron Ammeter

Properties

Maximum, 15-min. average and instantaneous value display
For x/1A or x/5A current transformers
Good readability
Exchangeable scale
High vibration and impact resistance
Terminal cover according to VGB 04 (option)

Description

Combined bimetallic instruments are intended especially for thermal monitoring of transformers, cables, etc. due to their slow reaction to current changes. They indicate mean r.m.s. current value during the measuring period of the instrument. The instrument does not react to short current pulses, essentially. Maximum mean value in a response time period is indicated by the red slave pointer. The latter can be reset or set to zero by means of a knob which can be sealed. Besides the bimetal system, the instrument also includes a moving-iron system which measures instantaneous r.m.s. values.

Variants

BEQ 72 72 x 72 mm for panel mounting

BEQ 96 96 x 96 mm for panel mounting

BEQ 144 144 x 144 mm for panel mounting

Mechanical Design

The system of the bimetal current meter consists of two bimetal spirals that are installed to work mutually. One bimetal spiral works current-driven, the other bimetal spiral compensates mutually working the ambient temperature, which can vary from -25 °C to +55 °C. A black pointer is coupled to this measuring system, which drags along a red pointer. This red pointer remains at the maximum value reached. The instrument also has a moving-iron movement for instantaneous value indication. The overload of the bimetal scale is 20 % and that of the moving iron is 100 %.