Se nti
nel C X T
Sentinel CXT Instruction Manual
Rev. 1.7
Page 4 of 49
The CXT alarms are used to activate annunciating devices when a gas reading exceeds a user-configured
threshold. There are three alarms (Alarm1, Alarm2 and Alarm3) and a fault condition. If installed, the
strobe is associated with Alarm 1, and the horn is associated with Alarm2. The external alarm connector
provides all alarm outputs (alarm 1, 2 and 3) for connection to external alarm devices. There are two types
of external alarm connectors: ‘Wet’ and ‘Dry’. The ‘Wet output connector provides 12V outputs for
external alarms or the two-strobe/four-strobe alarm bar. The ‘Dry’ output connector provides dry contacts
for external power to control external alarms. The field configurable user interface permits the user to set
alarm values and fault conditions to cause an assigned relay to fire, triggering external alarm devices. The
assigned relay outputs will return to normal state when a gas alarm or a fault condition clears. When the
alarm level is reached either the devices mounted to the box or attached to the external alarm connector are
activated, or both. An external manual switch can be wired to the CXT, acting as an acknowledge/reset
switch (Section 1.13).
When the CXT is in alarm, the display will remain on the channel group with the alarm. The user can
manually cycle to any group page that exists using the arrow switches. After a time out period, the CXT
will resume page cycle protocols based upon the existence of alarms/faults. Four LED indicators on the
front panel show alarm/fault alarm output status and are labeled respectively as ALM 1 (yellow), ALM 2
(yellow), ALM 3 (red), and FAULT (blue).
All alarms can be configured as Energized/De-Energized, Latching/Non-Latching and Silenceable/Non-
Silenceable for the relays.
Energi
z e d M ode
The normally open contact is closed if the alarm level has not been reached or if the sensor is not in fault.
Energized mode provides for fail-safe operation since a loss of power or cable failure will cause the contact
to be open.
D e -Energi
z e d M ode
The normally open contact is open if the alarm level has not been reached or if the sensor is not in fault.
Si
le n
ce a ble
The corresponding alarm LED and relay can be deactivated by acknowledging the Alarm Silence function
on the front panel of the CXT controller or by activating the external acknowledge switch if installed
(Section 1.13 and 5.2.2).
N on-Si
le ncea ble
The corresponding alarm LED and relay will remain activated until the cause of the alarm or fault is clear.
L a tchi
n
g M ode
The relay can only be deactivated by acknowledging the Alarm Reset function on the front panel of the
CXT controller or by activating the external reset switch if installed (Section 1.13 and 5.2.2).
N on-L a tchi
ng M ode
The relay is deactivated as soon as the sensor alarm or fault condition is clear.
1.4 P owe r Supply-Inte rnal R e cha rge a ble B a tte ry a nd C ha rgi
ng
A cce ssory
SmartWireless® CXT is powered by an internal rechargeable Smart Battery capable of delivering
continuous operation in a no alarm condition for two to eight weeks depending on the quantity and type of
sensors tied to the control panel. The internal re-chargeable battery pack shall only be charged in a non-
