AFR200 Series, Product User Guide
This document is subject to change without notice.
Caution: None of GAC products are flight certified controls including this item
Copyright © 2010, Governors America Corp., All Rights Reserved
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PUG4144 D
7.3.2 Installation Instructions
1. Install the oxygen sensor into the appropriate location by threading into the location determined from the
application considerations section finger tight.
•
Ensure the threads are not galled during this operation.
•
Use a 22mm wrench to tighten the oxygen sensor into place by 1/2 to 3/4 of a turn max. Take
caution not to over-torque the sensor and damage it.
7.4 Engine Coolant Temperature Sensor (ECT)
The engine coolant temperature sensor is an optional sensor provided from GAC. The coolant temperature
sensor is monitored by the AFR for engine protection in the event of an engine over temperature situation. These
limits can be calibrated within the AFR controller using SmartVU. A representation of the engine coolant
temperature sensor is shown in the following figure.
Engine Coolant Temperature Sensor
7.4.1 Application Considerations
•
The coolant temperature sensor should be located in the engine cooling water jacket prior to the
thermostat. The sensor is ideally installed in a coolant passage on the engine block since this location
represents engine temperature most accurately.
•
The sensor is mounted via a 3/8-18 NPT fitting.
•
The sensor is 0.35 in. [9mm] in diameter at the tip and 1.54 in. [29 mm] long from the tip up to the
retaining nut (end of threads).
•
In some installations require a tee fitting due to the lack of an available port on the engine block.
•
If this is the case, choose a coolant hose that has constant flow under all operating conditions. Do
not choose a hose that has flow dependant on whether or not the thermostat is open or closed.
•
Select a hose that is representative of the engine temperature and not a return line from the heater,
radiator, or CNG regulator for example.
•
Select a line that has a large amount of flow so that it is not susceptible to rapid fluctuations in
temperature due to wind and cold environmental conditions prior to the sensor readout.
•
If sourcing an alternate sensor the following specification must be met:
•
The sensor is of the Negative Temperature Coefficient (NTC) thermistor design. This implies that
resistance of the sensor varies inversely to temperature.
•
Choose a sensor that is electrically equivalent to VDO p/n 323 479 which has a range up to 250
°
F
[120
°
C] and is intended for single station applications with a floating ground (two terminals).
