Unigas PBY1025, Manual Of Installation - Use - Maintenance

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21
Immersion or strap-on sensors
Immersion probes installation
Sensors must be installed on the stretch of pipe in which fluid circula-
tes all the time.
The rigid stem (sensing element doing the measuring) must be inser-
ted by at least 75mm and must face the direction of flow.
Recommended locations: on a bend or on a straight stretch of pipe
but tilted by 45° and against the flow of fluid.
Protect them to prevent water from infiltrating (dripping gates, conden-
sation from pipes etc.) .
Installing QAD2.. strap-on sensors
Make sure fluid is circulating in the chosen location.
Eliminate insulation and paintwork (including rust inhibitor) on a min.
100mm length of pipe.
Sensors come with straps for pipes up to 100 mm in diameter .
Placing the probes (QAD22.../QAE21.../QAP21.../RCA...)
With pumps on outlet
with 3 ways valves / with 4 ways valves
Panel system / burner control
With pumps on return
with 3 ways valves / with 4 ways valves
Strap-on or immersion sensors?
QAD2.. strap-on sensors
Advantages :
z
10 sec. time constant
z
Installed with system running (no plumbing work)
z
Installation can be changed easily if it proves incorrect
П Limits:
z
Suitable for pipe diameters max. 100 mm
z
Can be affected by currents of air etc.
QAE2... immersion sensors
Advantages:
z
Measure "mean" fluid temperature
z
No external influence on measurement such as: currents of air,
nearby pipes etc.
Limits:
z
Time constant with sheath: 20 sec.
z
Hard to change installation position if it proves incorrect