Measure Pressure; Measure System Superheat/Sub-Cooling; Select The Refrigerant; Add And/Or Change Refrigerants - Cooper Atkins MFM300 Guide De L'utilisateur

First Press: T1 – T2;
Second Press: T1 – T3;
Third Press: T2 – T3;
Fourth Press: Delta T Display Off.

Measure Pressure

Connect a Cooper pressure transducer to either U1 or U2 (or both). The MFM300
will sense the probe(s) and display the pressure measurement(s) with the
appropriate U1 or U2 label. Before connecting the transducer(s) to the cooling
system, zero the pressure reading(s)(refer to Setup section on zeroing the pressure
probes and setting altitude).
Note: At sea level the pressure reading should be 0 PSI (0 kPA) when not connected
to a cooling system. At elevations above sea level the display will show a slight
negative pressure reading (-0.5 PSI/1000 feet altitude) Connect the transducer(s) to
the cooling system access ports, using best industry practices, to begin measuring
system pressure.

Measure System Superheat/Sub-Cooling

Select the Refrigerant: The selected refrigerant is displayed when in superheat/sub-
cooling mode, or when viewing pressure/temperature charts. To change the
refrigerant, press the REF button. The up/down arrows will appear beside the
refrigerant name. Use the up/down arrow buttons to scroll to the desired refrigerant
and then press the ENTER or REF button.
Press the CANCEL button to abandon changes.
Add and/or Change Refrigerants: The MFM300 stores P/T data from 15 popular
refrigerants that reside in permanent memory. There is room in the memory for up to
five more refrigerants. New refrigerant P/T data can be downloaded from the Cooper-
Atkins website ( www.cooper-atkins.com ) using the MFM300 Toolbox and the
optional computer connection cable.

Calculate Superheat/Sub-Cooling

The MFM300 can be used as a superheat/sub-cooling calculator. Connect the
temperature probes to the system and press the SH button. Select the refrigerant
and press the ENTER button. Since there are no pressure transducers connected,
system pressure will default to 25 PSI for superheat and 75 PSI for sub-cooling. You
may manually enter the actual pressure value from the manifold gauge into the
MFM300 using the up/down arrow buttons. Once the pressure is entered for
superheat, use the SHIFT button to move to sub-cooling, where pressure is manually
entered the same way. Remember that the values shown in this mode are not
dynamic.

Measure Dynamic System Superheat/Sub-Cooling

Measuring dynamic system superheat or sub-cooling requires both a temperature
probe and a pressure transducer. The refrigerant type selected on the display must
match the refrigerant type used in the system. Refer to the section Select the
Refrigerant. For superheat measurement, connect the temperature probe to T1,
and the pressure transducer to U1. For sub-cooling measurement, connect the
temperature probe to T2 and the pressure transducer to U2. To measure superheat,
attach the temperature probe to the system suction line near the compressor. Attach
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