TB 3211 Fan Speed Controller Change

16th February 2015

With immediate effect, the Saginomiya condenser fan speed controller has been changed to an Alco model.

All MCU+, CKC and MRC condensing units are now supplied with an Orange link between terminal 40 and 41.  The fan will run at full speed for commissioning when the link is fitted.

Simply remove the link for the condensing unit to run with fan speed control. Details for adjusting the controller and an example of a wiring diagram are shown below:

The new spare for this fan speed controller is 04401288 and is backwards compatible for replacing the previous controller. The previous fan speed control spare 55000487 is now obsolete.

The head pressure controller is factory set to suit the refrigerant. It may be necessary to adjust this to

suit site conditions, to raise or lower the nominal head pressure.

a. With the system switched off, connect a high pressure gauge to the liquid line service valve.

b. Switch on the system, and run for a few minutes to stabilise.

c. The head pressure should be approximately:

R407C: 275-280 psig (18.9-19.6barg) to achieve this remove sealing plug and insert 2mm or

5/64” allen key into setting screw. Turn allen key clockwise (+) or counter clockwise (-) to readjust the

setting. Do not turn setting screw more than 3 turns clockwise (+3). Use following table as a quick

guideline for setting:

Pressure changes per turn of adjusting screw:

Pressure change 1: 4.0 … 12.5 bar:

Clockwise ~ +1,2 bar, counter clockwise ~ -1,2 bar

Pressure change 2: 9.2 … 21.2 bar:

Clockwise ~ +2,5 bar, counter clockwise ~ -2,5 bar

Pressure change 3: 12.4 … 28.4 bar:

Clockwise ~ +3,3 bar, counter clockwise ~ -3,3 bar

After adjustment, re-insert sealing plug and make sure that it is properly fitted. IP65 protection

requires firmly sealed plug


Tolerances for condensing temperatures setpoint: ±2K

Min fan speed (0 rpm) and fan cut in pressure 200 psig (13.8 barg) are factory set and not adjustable.

NOTE: The condenser fan may stop if the operating pressure drops below 200 psig (13.8 barg)