MCC Control Board / DDC Control Board ReplacementASY-405-XXX / 290000201

Description

MCC Control Board / DDC Control Board Replacement ASY-405-XXX / 290000201

MCC Control BoardThe MCC Control Board is a fully-compatible replacement for the DDC® control board, offered with some Marine Air Systems® chillers. MCC is a complete, standalone chiller controller. In addition, up to 6 MCC control boards can be networked together using the MCC Master control board to operate a large, multi-stage chiller system.Marine Air Systems and DDC are a registered trademarks of Dometic Corporation

The Marine Chiller Control, identified in this document as MCC, can be used as a standalone or staged chiller controller to regulate loop water temperature in tempered watersystems. MCC also provides a level of protection against system damages caused by high or lowrefrigerant pressures, water flow problems, freezing of the compressor, and low line voltage.The MCC can be used to control directly connected compressors, VFD’s, reversing valves,electric heaters and system pumps.

Wiring

Controls must be connected as shown in the wiring diagram contained in this manual.High limit, freeze and return sensors must be the appropriate Microair sensor listed in thediagram. Switch inputs are dry contact only and must not have any outside connections tovoltage or current sources. External contactors must be used for water pumps over ½ HP,compressors over 2 HP, and for electric heaters.

Stand Alone Operation

Power ApplicationWhen power is first applied, the display will show the firmware revision for 2 secondsand then go blank if the mode switch is in the off position. Change the mode switch to selectheating or cooling.

Reversing Valve OperationIf a cycle is called within 75 seconds of a power restore or termination of a cycle, thereversing valve will toggle to equalize system pressures. This toggle will not occur if electric heatis enabled. The reversing valve will remain active when the compressor is active in heat mode.

Water Pump OperationThe circulating water pump (CWP) output will remain in operation whenever the modeswitch selects heat or cool. The seawater pump (SWP) output will cycle with the compressor orrun continuously depending on the “CON, dc” program parameter setting. See the programparameters section in this manual for more information.September 28, 2020 5 Rev 2.02

Operating ModesWhen heat or cool is selected on the mode switch, the display will alternate betweenshowing “SUP” (supply or outlet temperature measured by the freeze sensor), followed by thetemperature and “rtr” (return or inlet temperature) followed by the temperature. If the watertemperature deviation is 2° or greater from the set point, then the MCC will start a cycle. Thecompressor will start and continue to operate until the loop return temperature reaches setpoint.

Direct replacement for Dometic DDC control board 4220002