Description
Product description
Load current monitor with three measuring channels for monitoring three-phase isolating transformers with currents up to 32/63 A.
Typical applications
According to the standards set down for power supplies in medical locations (DIN VDE 0100-710 (VDE 0100-710), ÖVE/ÖNORM E 8007, IEC 60364-7-710), it overload protection of isolating transformers by disconnection is not allowed. Instead, monitoring of overload and high temperature is required for the medical IT transformer.
In combination with the isoMED427P or the 107TD47, the CMS460-D4 has the task of monitoring the load current for three-phase transformers.
Description of function
The currents are detected and evaluated as true r.m.s. values in the frequency range of 42…2000 Hz. All channels are scanned simultaneously so that the maximum scanning time for the three channels is ≤ 180 ms if 1x the response value is exceeded, and ≤ 30 ms if 5x the response value is exceeded.
The CMS460-D4 determines the maximum current of the three measuring channels and outputs this as a load value, which is reprsented as a percentage based on the response value. The currents of the three measuring channels are shown in the display in bar graph format and are available via the BMS bus on the channels 1…3. The latest maximum load value is available via the BMS bus on channel 4.
If the maximum response value of the load current is reached or exceeded the relays will be activated and an alarm is signalled via the BMS bus on channel 4 as soon as the response delay ton has elapsed. Both alarm LEDs on the device light up. CT connection faults are indicated via LED (Alarm 1) and can be queried via the BMS bus (channels 1…3).
History memory
The device utilises a history memory for fail-safe storing of up to 300 data records (date, time, channel, event code, measured value) so that all alarms can be traced back at any time (what happened when).
Analysis of harmonics
In addition to the load current measurement, the CMS460-D4 analyses the harmonics of the measuring channels 1…3 up to the order 40. The values are displayed as THF value (THF=Total Harmonic Factor).
Standards
• DIN VDE 0100-710 (VDE 0100-710)
• DIN VDE 0100-718 (VDE 0100-718)
• ÖVE/ÖNORM E 8007
• IEC 60364-7-710
