MSA
Appendix: Optional Internal Relays and RESET Button
ULTIMA X ® Series
94
GB
12.3 Alarm Relays
[
There are three alarm relays and one fault relay in the ULTIMA X
®
Series
Gas Monitors.
The three alarm relays will be activated if the sensor detects a gas concentration
that lies outside the limit values. The adjustment range of the alarm set-points is
0 – 60 % full scale. By default, the alarms 1, 2 and 3 are set at 10 %, 20 % and
30 % of the full scale reading and will be activated when the gas reading is above
these values. The oxygen model is an exception in the following cases:
-
Alarm 1 is set at 19 % oxygen and is activated when the oxygen reading falls
below this setpoint.
-
Alarm 2 is set at 18 % oxygen and is activated when the oxygen reading falls
below this setpoint.
-
Alarm 3 is set at 22 % oxygen and is activated when the oxygen reading rises
above this setpoint.
-
The adjustment range of oxygen alarm set-points is 0 - 25 Vol%.
These default setpoints can be changed or verified with the
ULTIMA/ULTIMA X Controller [
ULTIMA/ULTIMA X Series Controller and Cali-
brator Operating Manual]. In addition, the "latching alarm" option can be enabled
with the Controller.
Each alarm relay has one set of change over contacts [single pole double throw –
SPDT]. They are marked as follows:
-
NCD [normally closed when relay is de-energised]
-
C [common] or
-
NCE [normally open, when relay is energised].
ULTIMA X Series Gas Monitors are delivered with the alarm relays factory set to
the de-energised [no-alarm] position and the fault relay is set to energised [no-fault]
position.
Upon activation, the relay contacts change state and remain in this state as long as
the alarm condition exists within the ULTIMA® X Series Gas Monitor or latching
mode is selected. These defaults can be verified or changed with the
ULTIMA/ULTIMA X Controller.
[
"Instructions for resetting alarms" with the Calibrator/Controller in
chapter 5.1].
