CM Series Current Monitoring Devices | Technical Features

Technical specifications of CM Series Current Monitoring Devices are listed below:

CME series Multi-functional current relay, AC, overcurrent/undercurrent

The CME420 series current relays monitor undercurrent and overcurrent in AC systems as well as the current between two threshold values (window discriminator function). The currents are measured as r.m.s. values (AC). The currently measured value is continuously shown on the LC display. The measured value required to trigger the alarm relay is stored. Due to adjustable delay times, installation-specific characteristics, such as device-specific making currents, short-time current changes etc. can be considered. Current measurement is possible either directly or indirectly via standard current transformers (x/5 A). External supply voltage is required.

CME420

• Response value : 0,1 ... 16 A / 5 ... 999 A
• Supply voltage US* : DC 9.6…94 V , AC 16…72 V, 42…460 Hz  // DC 70…300 V, AC 70…300 V,
  42…460 Hz
• Rated frequency: 42 ... 460 Hz
• Functions : I< / I> veya I<, I>

CMD series three phase under / over current relay;

The CMD420/421 current monitoring devices monitor AC currents using three measuring inputs for overcurrent, undercurrent or undercurrent and overcurrent (window discriminator function). The currents are measured as r.m.s. values (AC). The currently measured values are continuously shown on the LC display. The respective measuring channel can be selected using the Arrow up or Arrow down button. The measured values causing the alarm relay to switch are stored. Due to adjustable delay times, installation-specific characteristics, such as devicespecific making currents, short-time current changes etc. can be considered.

For the measurement three standard current transformers are to be connected to the respective CMD420/421. The transformation ratio "n" of the current transformers (n = x/1A resp. n = x/5A) can be set up to a factor of n = 2000.

Then the actual current of the installation can be calculated by multiplying the measured current by factor "n" and indicated on the display. The currents can derive from a 3-phase system or from three different single-phase systems.

The CMD420/421 series requires external supply voltage

CMD420

• Response value : 0,1 ... 2kA / 0,5... 10 kA
• Supply voltage US : AC 16…72 V , DC 9,6 V…94 V, 15…460 Hz  //  AC/DC 70…300 V 15…460 Hz
• Rated frequency : 15 ... 460 Hz
• Functions : I< / I> veya I<, I>

CMS 460 multi-channel AC, pulsed DC sensitive load current evaluator;

The CMS460 system consists of one or several CMS460-D load current evaluators which are able to detect and evaluate load currents in earthed and unearthed power supplies via the associated measuring current transformers. The maximum voltage of the system to be monitored depends on the nominal insulation voltage of the measuring current transformer used in the case of busbar systems, or on the cables or conductors that are routed through.

W… (closed), WR… (rectangular) and WS… (split-core) and WF… (flexible) measuring current transformers are used for alternating and pulsating currents.

Any combination of the various measuring current transformer series can be connected to the evaluator measuring channels. Each CMS460-D utilises 12 measuring channels. Up to 90 load current evaluators can be connected via a BMS bus (RS-485 interface with BMS protocol), thereby up to 1080 measuring channels (sub-circuits) can be monitored.

If this product is to be used for fire or plant protection, the frequency response can be set accordingly. The measured currents can be analysed for harmonics.

CMS460

• Response value : 100 mA ...125A
• Supply voltage US : AC 16…72 V, 42…460 Hz ,DC 16…94 V // AC 70…276 V, 42…460 Hz,DC 70…276 V
• Rated frequency : 42 ... 2000 Hz
• Functions : I< / I> veya I<, I>