25 of 116
All relay contacts are rated 5 A Resistive 24 VDC -
250VAC.
The warn and alarm relays can be programmed for
energized (failsafe) or de-energized (non-failsafe). This
is done in the SYSTEM MENU. The latching or non-
latching operation is programmed for each channel
input. This is done in the CHANNEL MENU. When
programmed for latching operation, the reset button
must be depressed to release the relay from this
condition, but will only release the relay if the alarm
condition has passed. It is possible to have one or more
channels programmed as latching and one or more
programmed as non-latching. When this happens, if
channel inputs from both groups go into alarm/warn
then the latching program takes precedence over the
non-latching program.
Different corrective actions are normally required when
sensor/transmitters are located in dissimilar areas. Set
points could differ for the gases being monitored,
therefore, the common relays will not provide the
required results when this situation occurs. However
Scott Health & Safety has anticipated such situations
and can provide an optional remote relay assembly,
allowing alternative alarm combinations.
Fail Relay
The common fail relay is provided only to be used in
the energized state (failsafe). The remote relay
assembly allows for a relay to be configured as a non-
failsafe fault output. There are no set or reset timers
associated with fail alarms. When a fault is detected,
fail alarms are activated immediately. When the fault
conditions are cleared, fail alarms are immediately de-
activated.
When a fault condition is detected, the channel status
LED will change from a solid green to a flashing
yellow/green. It turns solid yellow if acknowledged by pressing the reset button.) The common fail relay will change
state from energized to de-energized.
If a channel is in a warn or a warn and alarm condition when a fault occurs on that channel, Table 1 defines the
relay(s) state when in a latched or unlatched programmed mode.
Table 1 – Relay States
(when in a Latched or Unlatched
programmed mode)
Summary of Contents for QuadScan II 7400
Page 10: ...5 of 116 Quick Start Programming Menu Tree...
Page 20: ...15 of 116 Figure 5 Mounting Dimensions of Model 7400...
Page 24: ...19 of 116 Figure 9 Battery Backup P N 096 0719 Outline Interconnection Wiring...
Page 60: ...55 of 116 Figure 13 Interconnect Wiring Between 7400 Remote Relay Assembly...