Filter
Top Products
Model TS420
Quick Start Guide
vi
NOTE - Power must remain disconnected until all wiring connections are made.
The absolute maximum distance between the TS420 and the power supply is 8000 feet (2438
meters). Depending on the application, general purpose or intrinsically safe, the cable length
will depend on the intrinsically safe barrier chosen and the cable used. See the Appendix,
Section 5.1.5, for the intrinsically safe system requirements. In addition, cable length
specifications can also be found in the Appendix, Section 5.1.3. In all cases, the cable run
should be as short as possible.
2. Apply power to the detector.
Before applying power to the system for the first time, all wiring connections should be checked
for correctness. The sensor should be allowed to stabilize prior to calibration. The stabilization
time should be one (1) hour for all sensors.
Initial Power-up
The TS420 has been shipped un-calibrated, therefore, the first time power is applied, the
TS420 will enter Start-up mode (3.6mA) for a short interval, then may transition to fault mode
(flashing MODE LCD with the CAL LCD off and the analog output current at 3.5mA) until
calibrated (See Section 4.3 for Calibration Procedure).
After calibration is complete, the TS420 will proceed to Operate mode (17.38mA = 20.9% V/V
O
2
) where any detected oxygen will show as a proportional analog output current between 4
and 20mA (4mA = 0% V/V O
2
, 20mA = 25% V/V O
2
). The MODE LCD will be on steady and the
CAL LCD off with normal atmosphere and both the MODE and CAL LCD's will flash when
oxygen deficiency is detected. (O
2
level < 19%).
General Monitors recommends the TS420 be calibrated again within the first twenty-four (24)
hours after the initial calibration. Calibrations should be performed with new units and units that
have been off power for more than one (1) week. See “Calibration”, Section 4.3, for more
details.
Power-up After Initial Calibration
When the TS420 is powered up, after it has been previously calibrated, the unit will enter a
Start-up mode (3.6mA) for approximately 50 seconds, which allows the sensor to stabilize
before proceeding to the Operate mode (17.38mA). During Start-up, the “MODE” LCD will
flash, the “CAL” LCD will be off and the analog output current will be 3.6mA.
OPERATING MODES INDICATOR ANALOG OUTPUT
CAL MODE
START-UP
❏ ✹
3.6mA
OPERATE
AMBIENT O
2
= 20.9%
❏ ■
17.38mA
DEFICIENT ATMOSPHERE, O
2
< 19%
1
✹ ✹
4.0-16.16mA
FAULT
NO POWER
❏ ❏
0.0mA
SYSTEM
❏ ✹
3.5mA
Figure Q-C Operating Modes, Indicators and Outputs
1. Segment may flash Synchronously or alternating.
Perform a calibration and the TS420 will return to operate mode (17.38mA).
NOTE - The TS420 will not allow you to enter calibration mode during Start-up mode (3.6mA).