Unit installation

803 C – 01/05 A – pag. 6/17
Figure 4 – Flow Switch
Table 1
Glycol Solutions
Use industrial grade glycols only. Do not use an automotive grade antifreeze. Automotive antifreeze contains
inhibitors that will cause plating on the copper tubes within the chiller evaporator. The type and handling of glycol
used must be consistent with local codes.
Evaporator and Condenser Water Flow and Pressure Drop
Flow rates must fall between the minimum and maximum values shown on the appropriate evaporator and
condenser curves. Flow rates below the minimum values shown will result in laminar flow that will reduce
efficiency, cause erratic operation of the electronic expansion valve and could cause low temperature cutouts.
Flow rates exceeding the maximum values shown can cause erosion on the evaporator water connections and
tubes. Measure the chilled water pressure drop through the evaporator at field installed pressure taps. It is
important not to include the effect of valves or strainers in these readings. Do not vary the water flow through the
evaporator while the compressor(s) are operating. MicroTech II control setpoints are based on constant flow.
Operating limits
PFS 106.1÷314.2 HFC 134a
Max evaporator leaving water temperature °C
15
Min evaporator leaving water temperature (without glycol) °C
4
Min evaporator leaving water temperature (with glycol) °C
-8
Min evaporator water ∆∆T (2 passes)
°C 4
Max evaporator water ∆∆T (2 passes)
°C 10
Min ∆∆T between leaving water evaporator and leav. water condenser
°C 16
Max ∆∆T between leaving water evaporator and leav. water condenser
°C 48
Max condenser leaving water temperature °C
55
Min condenser water ∆∆T (2 passes)
°C 4
Max condenser water ∆∆T (2 passes)
°C 10
NOMINAL PIPE
SIZE INCHES (MM)
MINIMUM REQUIRED FLOW
TO ACTIVATE SWITCH –
LITERS PER SECONDS
5 (127) 3.7
6 (152) 5.0
8 (203) 8.8
Flow direction marked on switch
NPT flow switch connection
Tee