System description
18
RCMS460-490_D00067_03_M_XXEN/12.2017
3.2
Description of function
The currents are detected and evaluated as true r.m.s. values in the frequency
range of 0 (42)…2000 Hz. All channels are scanned simultaneously so that the
maximum scanning time for all channels is ≤180 ms if 1 x the response value
is exceeded and ≤ 30 ms if 5 x the response value is exceeded.
The latest current values of all channels are shown on the LC display in bar
graph format. If one of the two set response values is exceeded, the response
delay
t
on
begins. Once the response delay has elapsed, the common alarm re-
lays "K1/K2" switch and the alarm LEDs 1/2 light up.
Two response values/common alarm relays, which can be set separately, al-
low a distinction to be made between prewarning and alarm. The faulty chan-
nel(s) and the associated measured value are indicated on the LC display. If
the current falls below the release value (response value plus hysteresis), the
release delay "toff“
t
off
begins. When the release delay has elapsed, the com-
mon alarm relays switch back to their initial state.
If the fault memory is enabled, the common alarm relays remain in the alarm
state until the reset button is pressed or a reset command is sent via the BMS
bus. The device function can be tested using the test button. Parameters are
assigned to the device via the LC display and the control buttons on the front
panel of one of the connected RCMS…-D devices or via connected panels,
Ethernet gateways (z. B. COM460IP) and Condition Monitors (z. B. COMTRAXX
CP700). With the adjustable preset function the response values can set for all
channels taking the latest measured value for each channel into account.
Digital input
Each individual channel can be used for one of the following monitoring func-
tions:
– As digital input using a potential-free contact 1/0
– Or for current or residual current monitoring in combination with
measuring current transformers.