Model S4000CH
22
Figure 18: Relay Reset
The relays can be reset via the Remote Reset input terminals on TB2. Connect a
normally open switch between terminal TB2-7 and TB2-8. Closing the switch
momentarily will reset the relays. General Monitors explosion-proof switch, P/N
30051-1, can be used for this purpose. See Section 7.6 for ordering instructions.
The relays can be reset via the Modbus Interface (Section 6.0).
The relays can be reset via the HART communication.
NOTE:
Red LED’s above and below the digital display indicate that the Alarm and Warn
relays are active. Latching relays can only be reset if the gas concentration has fallen
below the respective relay set point.
3.10 User Selectable Options
The S4000CH includes many selectable options to provide the user with the most flexible
combustible gas detector possible. These options include Adjustable Calibration Level, Warn
and Alarm Relay Set Points and Configuration, and Modbus Communications Settings.
These allow the unit to operate with a wide variety of PLC and DCS Systems. The following
sections explain the available options and how they can be customized. A flow diagram is
included to help the user in understanding the process of reviewing and changing the
available options (Figure 19).
NOTE:
If the unit was ordered without relays or Modbus communications, changing relay or
Modbus settings will have no effect on the operation of the unit.
3.11 Available Separate Purchase Options
Modbus
Dual
Redundant
Modbus
Single Modbus and HART
HART
HART is a Master to Slave -One to One communication channel.
RGC
The Remote Gas Calibrator (RGC) is an accessory that allows remote calibration.
With this device, the user turns on and off the calibration gas manually.
ARGC
The ARGC accessory is an Automatic Remote Gas Calibrator (ARGC). It is a kit
with a RGC, a solenoid valve and all the required fittings from the valve to the
RGC.
Remote Mounted ARGC
The ARGC is also available in a standard GM explosion proof box. This provides
terminal strips for all the connections to activate the ARGC.
