Connecting The Automatic Purge And Calibration Check System - Novatech 1732 Technical Manual

The watchdog timer is a special alarm. There will not be an alarm message displayed, but the transmitter
will reset.
Alarms can be accepted by pressing the A
button.
Alarm Relay 2 to 4
High Oxygen 1 / Oxygen 2
Low Oxygen 1 / Oxygen 2
Very Low Oxygen 1 / Oxygen 2
Oxygen Deviation

4.13 Connecting the Automatic Purge and Calibration Check System

The purge and calibration solenoid valves are supplied with mains voltage. This supply has electrical shock
danger to maintenance personnel. Always isolate the transmitter before working with the purge and
calibration solenoid valves.
The on-line auto purge and calibration check system is optional. For details on its operation see chapters
4.19 Filter Purging, 4.20 Calibration Gas Check and Chapter 11. Gas Calibration Check and Purge.
To automatically sense a blocked probe filter, a flow switch should be installed in the 'purge' line to the probe
'CAL' port. It should be adjusted so that it energises just below the purge flow with new or clean filters
installed. The flow switch contacts should be connected to terminals 16 & 17 (FLOW SW).
If the filter is still blocked or partly blocked after an auto purge cycle, the flow switch will not energise and will
therefore cause a 'Probe1 (2) Filter Blocked' alarm.
After installation the purge/cal system should be tested thoroughly for leaks. Any leaks can cause significant
errors if the flue is at negative pressure. If the flue is at positive pressure, an outward leak can cause
corrosion in the purge/cal system piping and fittings.
If probe/filter purging is required but a "Probe1 (2) Filter Blocked" alarm is not required, do not install the flow
switch but link terminals 16 &17.
To Oxygen Probe
Cal Port
(optional) Flow switch for blocked filter alarm
Technical Manual
24
LARM
Select any one or all of the following for each relay. See Chapter 9. Alarms
Solenoid 1
Solenoid 2
Calibration Check Gas flowmeter/regulator
5 litres/minutes (10 scfh)
ChemTec LPH-125-7
 button (viewing the alarm messages) and then the E
Probe 1 / Probe 2 Temperature Low
Calibration Check 1 / Check 2 in Progress
Probe 1 / Probe 2 Purge in Progress
CAUTION
40 Cal / Purge Solenoid 1
39 Cal / Purge Solenoid 2
38 Solenoid Common
Cal Check Gas
140kPa (20PSI) Max
Clean and Dry Purge
Air Supply
140kPa (20PSI) Max
NTER
Automatic Purge &
Calibration check System
Wiring Schematic
Automatic Purge &
Calibration check System
Piping Schematic
August 2018
1732 Oxygen Transmitter