22nd January 2005

A new 0.5m lift pump has been introduced on all Airking and Marstair cassettes as from serial number 1057995.

The flow rate is equivalent to the earlier model and there are a number of improved features:-

* The pump runs on demand from the float switch, in any mode (the original pump operated on demand from the cooling signal). This will extend the lift pump system life, as the pump only operates when needed.
* There is no run-on  timer, making the pcb less complicated 
* The discharge hose is fitted with a non-return valve. This will eliminate flood back when the pump stops, avoiding float bounce and unwanted water noise.
* The fuse is more accessible, located off the pcb, in the external electrics box.

As before, the alarm signal, generated by the highest float position, will stop cooling (stops the compressor in refrigeration systems, or closes the valve in chilled water fan coils). The pump will run until the high water level is cleared and the lower float position is reached.

The spare of the pump assembly, part number 55201100, is backwards compatible with the old pump assembly.
Individual pump components are not backwards compatible.
A new site-fit kit is also available for the occasional requirement where gravity drain units were supplied.

Part numbers and list prices as follows:

97101150   PCB for lift pump   £31.50
97101151   Lift pump + bracket £72.45
97101152   Non return valve/hose £12.60
97101153   Float switch  £28.35
55201100*  Lift pump assembly (backwards compatible) £110.25
55200340  Lift Pump Kit (600/875) £100.00

* This will replace the individual components for the old pump when they are no longer available.

Site identification

Should a site problem occur and identification of the lift pump is in doubt, the notes below will be of assistance:

Old Pump - Stainless steel bracket, Green pcb, Pump fuse on PCB and white/translucent hose on pump outlet   

New Pump - Galvanised sheet metal bracket, White pcb, Pump fuse in electrics box and black hose on pump outlet