Changing Set Point; Regulating Pressure/Flow - ATC G04 Series Installation, Operation & Service Manual

Applied Thermal Control Ltd
39 Hayhill Industrial Estate
Barrow-upon-Soar, Loughborough
LE12 8LD, United Kingdom
+44 (0) 1530 839 998
Service@thermalexchange.co.uk
Support@app-therm.com
5.1

CHANGING SET POINT

1
Push and hold the enter button
2 Use the up and down arrows to set the temperature
3
Press enter button
4 The set value now will be activated, and the chiller will start
5.2

REGULATING PRESSURE/FLOW

This arrangement comprises a positive displacement pump (most commonly a rotary vane type)
with a spring-loaded pressure relief valve to provide better overpressure setting control with
minimal flow losses compared to fixed orifice bypasses/reliefs. This annex describes ATC's default
settings and how to adjust the system.
It is important to understand the basic principle that all else being equal, higher flow results in a
higher demand for pressure. The motor generates the power required to turn the pump head and
create that pressure. The more restrictive a water circuit is, the higher the pressure required to
maintain flowrate. Positive displacement pumps are designed to generate high pressure and are
mechanically tight - their RPM dictates flowrate. See image above.
1 Pump discharge – fluid leaves the pump head and enters the gauge-tee assembly. It passes
the temperature sensor at the tee, and when the pressure relief is inactive, fluid heads
towards no. 2.
2 Outlet to process – fluid heads out of the product to the application. Whatever restrictions
lie downstream, fluid leaving this point has not passed through the pressure relief valve.
3 Pressure gauge connection – connection to a pressure gauge on the front panel of the
product. This displays the pressure in the water circuit, at the pump outlet, not the
application which will be lower.
4 Pressure Relief Valve (PRV) – spring tension in the body of the PRV determines whether fluid
travels through point 2 or passes through to point 7.
Installation, Operation & Service Manual
until it shows "SP 1"
again to set the temperature
POSITIVE DISPLACEMENT PUMPS & DISCRETE PRESSURE RELIEF VALVE
G04/K04
ACHIEVING DESIRED SET POINT
Rev 1 – 05/04/23