Fieldpiece HG3 - Wireless HVAC Guide System Analyzer - Manual (Page 34)

www.fieldpiece.com www.fieldpiece.com www.fieldpiece.com www.fieldpiece.com www.fieldpiece.com www.fieldpiece.com www.fieldpiece.com www.fieldpiece.com www.fieldpiece.com www.fieldpiece.com www.fieldpiece.com
6 6 6 7
Appendix
CheckMe! Diagnostics
5.4 Indoor Coil Airflow Diagnosis
5.401 Airflow OK:
The indoor coil airflow was directly measured using
the TrueFlow® grid and is OK.
5.402 Probable OK airflow:
The indoor coil airflow was tested by an
indirect means (temperature split) and is probably OK.
5.403 Airflow unknown, check airflow: The measurements are
insufficient to diagnose the indoor coil airflow. Either measure the
Return Plenum Dry Bulb, Wet Bulb and Supply Plenum Dry Bulb or use
a TrueFlow® Plate.
5.404 Low airflow, increase airflow until actual temp split
matches target temp split. Actual temp split is __°F and
target temp split is __°F:
The indoor coil airflow is low based on
the temperature split. Check the filter and coil, inspect for any restrictions
and blockages. Make sure all registers are open. If the airflow remains low,
consider increased blower speed and duct system modifications. Supply
and return plenum static pressures can be used to diagnose the causes of
low airflow.
5.405 Low airflow, increase airflow:
The indoor coil airflow was
directly measured using the TrueFlow® grid and is low. Check the filter
and coil, inspect for any restrictions and blockages. Make sure all registers
are open. If the airflow remains low after a retest, consider increased
blower speed and duct system modifications. Supply and return plenum
static pressures can be used to diagnose the causes of low airflow.
5.406 Low capacity or possible high airflow, measure airflow
directly:
The temperature split is low. This usually means that the
capacity of the system has been reduced due to incorrect refrigerant
charge. Higher than expected airflow is rare, but does occur occasionally.
Measuring the airflow directly would identify if high airflow is the cause
of the low temperature split.
5.407 High airflow, possibly reduce airflow:
The indoor coil
airflow was directly measured using the TrueFlow® grid and is higher
than expected. Consider reducing the airflow particularly if the unit is
in a damp climate. In heat pumps high airflow causes uncomfortably low
delivery temperatures.
5.408 Possible plenum temperature measurement error,
retake plenum temperatures:
The reported wet and dry bulb
temperature readings from the return and supply plenums are unlikely.
Retake the measurements in the INPUT FORM. See Return DB and
Return WB sections for detailed instructions on how to take these
measurements properly.
5.5 Refrigerant Charge Diagnosis
5.501 Charge OK:
Refrigerant charge tested and it is OK.
5.502 Possible OK charge: The primary indicator of refrigerant charge
(subcooling for TXV/EXV or superheat for non-TXV) indicates the
refrigerant level was OK. However, a secondary indicator reduces the
confidence in that diagnosis. Check out any other potential problems
indicated.
5.503 Charge unknown, check charge:
The measurements are
insufficient to diagnose the refrigerant charge. For best results return to
the INPUT FORM by pressing the INPUT button and fill out the INPUT
FORM completely before pressing the OUTPUT button again.
5.504 Possible undercharge, possibly add refrigerant:
Try fixing
other conditions first and retesting but if this diagnosis persists the system
may be undercharged, if no other conditions are triggered, consider
adding refrigerant to correct. The amount of refrigerant to add will vary
based on the size of the system and the difference between Target and
Actual superheat/subcooling.