Julabo F12 - Description; Refrigerant Circuit; Operation Principle of the Cooling System; Setup

Description
4
1. Description
The JULABO Refrigerated Circulators are compact bench-top models consisting of the refrigerating
bath unit and circulator.
Regarding the circulator, please refer to the separate service manual.
The refrigerating bath units are equipped with virtually noiseless and vibration-free cooling
machines containing a sealed compressor. The cooling energy is indirectly transferred via the
stainless steel cooling coil (evaporator) located in the bath tank. A powerful ventilator fan carries
the condensation heat away from the condenser and cooling machine.
2. Refrigerant circuit
Capillary
throttling tube
Injection channel
Filter dryer
Liquid channelHot gas channel
Compressor
Schrader valve
Suction channel
Bath tank
Cooling coil (evaporator)
Condenser
2.1. Operation principle of the cooling system
The cooling machine draws heat from the bath liquid via the cooling coil (evaporator) located in the
bath tank. This heat is exhausted via the ventilated condenser.
The compressor is equipped with a thermal overload protection device that trips if the temperature
rises impermissibly, and then, following a cool-down phase, automatically cuts out again. The
length of the cool-down phase also depends from the ambient temperature.

Before investigating defects, proper operation of the electronics and then of
the refrigerant circuit must be verified.
3. Setup
 Place the unit in an upright position.
 The fresh air intake is at the front of the unit, exhaust air is at the rear.
 Wall distance at least 20 cm.
 Do not obstruct the ventilation.
 Do not modify the venting grids.
 Ambient temperatures above 20 °C result in reduced cooling efficiency.
 The overload protection device could be tripped at ambient temperatures above 35 °C.
 Do not set up the unit in the immediate vicinity of heat sources and do not expose to sun
light.