TESTO 549, Instruction Manual

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6 Using the product
16
Display Mode Function
Refrigeration
system Normal functionality of the digital
manifold
Heat pump Normal functionality of the digital
manifold
Automatic
mode If the automatic mode is activated, the
testo 549 und testo 550 digital
manifold automatically changes the
display of the high and low pressure.
This automatic change occurs when
the pressure on the low-pressure side
is 1 bar higher than the pressure on
the high-pressure side. During the
change,
Load (2 s) is shown in the
display.
This mode is especially suited to air
conditioning systems which cool and
heat.
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6.2. Performing the measurement
WARNING
Risk of injury caused by refrigerant that is at high pressure,
hot, cold, or poisonous!
> Wear safety goggles and protective gloves.
> Before pressurizing the measuring instrument: Always fasten
the measuring instrument at the suspension device in order to
prevent it from falling (risk of breakage)
> Check if the refrigerant hoses are intact and connected
correctly before each measurement. Do not use a tool to
connect the hoses. Only tighten the hoses by hand (max.
torque 5.0 Nm/3.7 ft*lb).
> Maintain permissible measuring range (0 to 60 bar). Pay
particular attention with systems with refrigerant R744, as
these are often operated with higher pressures.