I 2 C Watch Dog Circuitry; Heater Control; Figure 6-10. Relay Board Status Led Locations; Table 6-1. Relay Board Status Leds - Teledyne T400 User Manual

Table 6-1. Relay Board Status LEDs

LED COLOR
D1 RED Watch Dog Circuit
D2 YELLOW Metal Wool Scrubber Heater
D3-D6
D7 GREEN Zero/Span Gas Valve
D8 GREEN Measure/Ref Valve
D9 GREEN Sample/Cal Gas Valve
D10-D14
D15 GREEN Photometer UV Lamp Heater
IZS O
D16 GREEN
1 Only present when the Z/S valve option is installed.
6.3.3.2 I 2 C WATCH DOG CIRCUITRY
Special circuitry on the relay board monitors the activity on the I
D1. Should this LED ever stay ON or OFF for 30 seconds, the watch dog circuit will
automatically shut off all valves as well as turn off the UV sources and all heaters. The
Sample Pump will still be running as it is not controlled by the relay board.
6.3.3.3

HEATER CONTROL

In the base version of the Model T400 photometric analyzer, there is only one DC heater
operated by the relay PCA. It is attached to the Photometer UV Lamp housing and
maintains the temperature of the UV Lamp at a constant 58ºC.
Additional DC heaters also controlled by the relay PCA, are included in the following
optional components:
083730400A DCN8130
FUNCTION
Cycles On/Off every 3 seconds under direct control of the analyzer's
CPU.
Valve Open to SPAN GAS FLOW
1
Valve Open to REFERENCE path
2 Valve Open to CAL Gas Flow
Generator UV Lamp
3
Heater
2 Only present when either the Z/S valve option or the IZS valve option is present.

Figure 6-10. Relay Board Status LED Locations

Teledyne API – Model T400 O
STATUS WHEN LIT
HEATING
SPARE
SPARE
HEATING
HEATING
Analyzer
3
STATUS WHEN UNLIT
NOT HEATING
Valve Open to ZERO GAS FLOW
Valve Open to MEASURE path
Valve Open to SAMPLE Gas Flow
NOT HEATING
NOT HEATING
2 C bus and drives LED
153