11
JMNC Operating Instructions
3 Design and Function
3.2.3
Underspeed Monitoring/Switching Function
(with run-up bridging)
During the set run-up bridging period the output relay (
16
)
is attracted
.
After expiration of the run-up bridging period, and when
the drive operates with a constant rotational speed, the
output relay (
16
) remains attracted and the green LED (
5
)
lights. The orange LED (
4
) flashes in the cycle of the in-
coming pulses.
Underspeeding of the nominal rotational speed
If the set rotational speed is not reached, the output relay
(
16
) drops and the green LED (
5
) extinguishes
Rotational speed
monitoring
device
the following relay contacts are
closed
JMNC
8 and 10
Rotational speed
monitoring
device
the following relay contacts are
closed
JMNC
9 and 10
J
Switched speed
II
V
III
Standard operation
Run-up
Malfunction
I
IV
green LED (
5
) on: output relay (
16
) attracted
green LED (
5
) off: output relay (
16
) dropped
Item Description
Contact closed
green
LED
JMNC
I
relay triggering time,
t = 200 ms
9 -10
II
without run-up
bridging
9 -10
III
with run-up bridging
8 -10
IV
number of pulses
above nominal val-
ue
8 -10
V
number of pulses
below nominal value
9 -10
pulses/min.
Rotational speed
of the drive
Operating speed
Fig. 3-2: Time table for underspeed counter
