Carrier-Apac, in Perth Western Australia, was a subsidiary of a $35B world-wide
air conditioning conglomerate. The Apac strong suit was large, multi-stage
reverse cycle "heat pump" units, of the type that get hoisted onto the roofs of
factories and office buildings using a crane or helicopter. Apac were
controlling their units with a mash-up of single stage controller boards, made
by a sister company, plus sundry relays and timers. It was basically a mess. It
was costing them dearly in skilled labour to wire it all up and test it, and it
didn't provide any of the flexibility demanded of modern systems.
In 2000 we were invited to propose a better solution. The final outcome was the
CA20 air conditioner controller. The CA20 is a two-stage controller, and two of
them can be ganged together via a simple cable to control 4-stage heat pumps.
It includes dedicated circuitry for safety interlocks (even if the processor
goes berserk, the safety "chain" will work), a number of 24VAC relays for
controlling solenoid valves, and two heavy duty relays for directly controlling
240V outdoor fans. It features a simple numeric fault code readout, which
greatly assists service technicians. As part of the development we wrote a
Windows program that connects to the CA20 and provides production line
commissioning and diagnostic information.
A couple of years into production of the CA20 Apac's chief engineer, John
Vivian, told us how pleased they were with the CA20. The build quality was
excellent, and the production-friendly design had literally doubled the
capacity of their production area by streamlining throughput. Cost were reduced
by reducing the labour skill level required, in addition to the amount of labour
required. All in all they were reaping indirect benefits from a custom SPLat
controller that well exceeded the obvious direct B.O.M. cost reduction.
Read his letter.
Apac was closed down by Carrier corporate in 2009, in the wake of the global
financial crisis. One can only wonder why a successful operation, with exports
as far afield as South Africa, Saudi Arabia and Siberia would be dumped, but it
was certainly nothing to do with our controller. However, all is not lost for
SPLat! The CA20 became almost legendary in the commercial/industrial HVAC
industry in Australia, because the technicians love it for its reliability and
diagnostic features. We are therefore now offering a newer, modernised design,
the HVAC26 (pictured) to the industry in general.
It rests solidly on all that was good in the CA20, but with a number of new
features to make it even better to use. The CA20's reputation has also led to
us being invited to engineer a number of custom control systems related to
energy saving and the management of air-conditioners in Australia's huge mining
industry.
Carrier-Apac
Industrial air conditioners
Controller type:Custom controller
Key features:All factory connection via plug-ins; hardwired safety circuitry;
2 thermistor temperature circuits; diagnostic readout; 24VAC power;
custom Windows program for factory commissioning
Programming:Done by SPLat
Relationship:From 2000 thru 2009
SPLat advantage:Reduced labour costs, reliability, ease of end-product field
servicing.