Unity Board Micro Air Corporation Phone (609) 259-2636 124 Route 526. WWW.Microair.net Allentown NJ 08501 Fax (609) 259-6601 January 11, 2016 1 Revision 1.02
Introduction The Unity board is a next generation module that incorporates the features of the SMX II, Q-Logic and Passport IO control boards in a single control board. The Unity board is designed to replace these three control boards in all future Dometic products. One of the design goals for this module was that it be plug and play compatible with the legacy controls it replaces. Displays connected to this module should function and behave as though they were connected to the original legacy controller. Temperature sensor selection is now standardized with the Unity module. All systems manufactured by Dometic from 1/1/2016 on are now equipped with Cruisair TSEP sensors. Marine Air Systems replacement applications can still use the old marine air sensors by cutting the RES SEL (JP5) jumper. All temperature sensors connected must be the same type sensor. Cruisair applications must only use Cruisair TSEP sensors. Unity has been tested and approved for use with the following displays: Passport IO Passport IO Compact Passport Elite SMX ir SMX II-AB SMX ht Q3 Qht Smart Touch Computer area network (CAN) bus operation is possible by ordering the board with a factory installed option board. A complete CAN message specification is available at: http://www.microair.net/main/products/manuals/airnet_can_bus_protocol.pdf A factory installed integrated EasyStart option board is also available. This option saves space while reducing compressor starting current. Applications with marginal AC power supplies such as small generators and weak dock power can benefit from EasyStart. AC ground for AC mains and any board connected equipment must be attached to a ground stud within the electric box. January 11, 2016 2 Revision 1.02
Connections and Jumpers Figure 1: 1. RES SEL (JP5): This is the standard configuration for all Marine air systems made after 1/1/2016. When this jumper is uncut and the display is connected to MA DISPLAY (8), all temperature sensors must all be Cruisair TSEP sensors (3K ohms at 25 C thermistors). When the jumper is cut, all temperature sensors must be legacy Marine Air Systems sensors (10K ohms @ 25 C). Cruisair displays are not affected by cutting the jumper. 2. CW ENABLE: Cut this jumper in any chilled water or tempered water application when using the control as an air handler. 3. LP ENABLE: Cut this jumper in any direct expansion application where a low refrigerant pressure switch is connected. Also cut this jumper in Cruisair SMX tempered water (TW) applications when a changeover stat is used. 4. DC: This is for direct connection to a DC fan. Only ground (-) and signal (+) connections are required from the fan. If the fan has a positive voltage supply connection it should be left disconnected. Properly terminate and insulate the fans + connection to prevent damage to the fan s electronics. 5. HP: High refrigerant pressure, dry contact switch connection. Also used for connection to a humidistat in Cruisair SMX tempered water (TW) applications. 6. GND: Common ground for HP (5) and LP (7) connections. 7. LP: Low refrigerant pressure, dry contact switch connection. Also used for connection to a changeover stat in Cruisair SMX tempered water (TW) applications. January 11, 2016 3 Revision 1.02
8. MA DISPLAY: Standard 8-wire connection to Marine Air Systems displays. 9. CA DISPLAY: Standard 6-wire connection to Cruisair displays. 10. INSIDE: Inside or alternate air sensor connection for measuring ambient temperature. Usually installed in the return air stream. 11. H2O IN: Water inlet temperature sensor for chilled or tempered water applications. 12. H20 OUT: Optional water outlet temperature sensor in Cruisair Q-Logic tempered water applications and the optional pump sentry sensor Marine Air Systems direct expansion (DX) applications. 13. OAT: outside air temperature sensor. 14. Heater Triac: Optional triac output that drives an electric heater. 15. L2: AC line 2 power input. All L2 connections on the board are common and electrically connected together. 16. COMP L2: Common L2 connection. 17. FAN L2: Common L2 connection. 18. PUMP L2: Common L2 connection. 19. PUMP L1: Pump output. 20. L1: AC line 1 power input. 21. COMP L1: Compressor output. 22. VALVE L1: Reversing or water loop bypass valve. 23. FAN L1: Fan or blower output. January 11, 2016 4 Revision 1.02
Legacy Board Replacement Replacing the Passport IO The chosen footprint for the Unity board was the Passport IO footprint making it mechanically a drop in replacement for these controls. Optional heater triac is not required for this application. Sensors for the system may be Cruisair TSEP or Marine aair Systems sensors. Marine Air Systems sensors require cutting RES SEL (JP5) to enable the 10K sensor selection. Chilled Water (CW) or Air Handler (AH) applications with inlet water in sensor, Direct Expansion (DX) applications with pump sentry sensor or any application with an outside air sensor will need 2 pin to 6 pin adapters available from Dometic to use Marine Air Systems sensors. Cruisair sensors are available in two or six pin configuration. To avoid the need for the adapters, installers should consider replacing all sensors with Cruisair sensors in these applications and leave RES SEL (JP5) uncut. The numbers in yellow circles in the top diagram translate the connections in the red circles in the lower diagram. If JP1 or JP3 are cut on the Passport IO board, the respective jumpers must be cut on the unity board. CW Notes: CW ENABLE must be cut on the Unity board. DX Notes: Electric heater must be connected through a contactor connected to the valve output (22) in systems equipped with electric heat. January 11, 2016 5 Revision 1.02
Replacing the Q-Logic Existing Q-Logic electric boxes would need mechanical modification or replacement to accommodate the footprint of the Unity module. An optional heater triac is required only if AUX heat is used in DX applications. System wiring, based on the standard Cruisair colors indicated in the manual is: Tempered water applications: (20) Black [L1] (15) White/Red [L2] (23) Orange [Fan/Blower] (22) Blue [Valve] (21) Purple [Aux Heater] (14) Purple[AUX Heater] Direct Expansion (DX) Applications: (15) White/Red [AC L2] (16) White/Red [Compressor Run] (17) White/Red[Blower L2] (17) White/Red[Valve L2] (18) White/Red[Pump L2] (19) [Pump L1] (20) Black[AC L1] (21) Purple[Compressor Com] (22) Blue[Valve L1] (23) Orange [Fan L1] (14) Red [Aux Heater] (5) Yellow[HP Switch] (7) White[LP Switch] (6) One yellow and one white from LP and HP switches spliced together. TW Notes: CW ENABLE must be cut on the Unity board. DX Notes: The above wiring separates the pump and compressor on two different outputs. This allows the pump to start several seconds before the compressor. The pump may also be wired to the compressor output if desired. January 11, 2016 6 Revision 1.02
Replacing the SMX II Existing SMX-II electric boxes would need mechanical modification or replacement to accommodate the footprint of the Unity module. An optional heater triac is not required for this application. The compressor output is used for AUX heat in TW applications. System wiring, based on the standard Cruisair colors indicated in the Cruisair manual is: Tempered water applications: (20) Black [L1] (15) White/Red [L2] (23) Orange [Fan/Blower] (22) Blue [Valve] (21) Purple [Aux Heater] (7) White[Change Over Stat] (5) [Optional Humidistat] (6) Common connection for Humidistat and change over stat Direct Expansion (DX) Applications: (15) White/Red [AC L2] (16) White/Red [Compressor Run] (17) White/Red[Blower L2] (17) White/Red[Valve L2] (18) White/Red[Pump L2] (19) [Pump L1] (20) Black[AC L1] (21) Purple[Compressor Com] (22) Blue[Valve L1] (23) Orange [Fan L1] (5) Yellow[HP Switch] (7) White[LP Switch] (6) One yellow and one white from LP and HP switches spliced together. TW Notes Electric heater may connect to Triac, P7, P9, or Term2 in legacy installation. Connect heater to COMP L1 in the Unity installation. January 11, 2016 7 Revision 1.02
CW ENABLE must be cut on the Unity board. DX Notes: The above wiring separates the pump and compressor on two different outputs. This allows the pump to start several seconds before the compressor. The pump may also be wired to the compressor output if desired. Compressor may connect to triac, P7, P9 or Term 2 in the legacy installation. Connect the compressor to COMP L1 in the Unity installation. EasyStart The EasyStart option board can reduce starting currents by over 50% and minimize flickering lights caused by poor dock power and generator loading problems. The EasyStart option can be selected for compressors with RLA of <= 22 Amps. Larger compressors should use an external EasyStart that supports higher RLA values. EasyStart Troubleshooting If a fault is detected by EasyStart it will illuminate some or all of the three trouble lights on the top of the control board. Evaluation and identification of these faults should only be performed by properly trained service personnel as access to the electrical box is required. No Start Winding Zero Cross: No signal is detected from the start winding of the compressor with power applied. Improper wiring, a bad start capacitor, open fuse F1, or bad compressor can cause this fault. Power Interrupted: power was lost for several cycles and then returned. This can be caused by power switching or buck boost transformers. Because the compressor can stall in less than 100mS, EasyStart will shut down for 3 minutes then attempt a restart. Compressor Stall: EasyStart attempted to start and did not see the correct conditions to determine a correct start. This can be caused by a bad or incorrect start capacitor or open fuse F1 on the board. Compressor Over Current: A sustained compressor current of >30 amps was detected. Open Compressor Overload: The compressor overload protection has opened or the compressor has lost the connection to the common winding. January 11, 2016 8 Revision 1.02
Wiring Consult the Dometic owner s or service manual for the system for standard wiring diagrams. The EasyStart option board wiring is provided below for system upgrades. EasyStart Wiring January 11, 2016 9 Revision 1.02
Specifications: General: Temperature sensor accuracy 2 F at 77 F Low voltage limit 115 VAC units 75VAC Low voltage limit 230 VAC units 175VAC Line voltage limit 250VAC Frequency 50 or 60 Hz Maximum board input current 30 Amps Minimum operating temperature 0 F Maximum operating temperature 180 F Maximum RH conditions (Board and display) 95 % Non-condensing Maximum length of the display cable 75 Feet Maximum length of any temperature sensor cable 75 Feet Applications Direct Expansion (DX) Fan output Valve output Pump output Compressor output Electric Heater Air Handler (AH) Electric heater output: Connected to compressor L1 and L2 External Triac: Valve output MAX Fan output MAX EasyStart Replacement fuse Maximum compressor size 6 Amps 5 Amps Maximum ¼ HP at 115 VAC ½ HP at 230 VAC 1HP at 115 VAC 2HP at 230 VAC 26 Amps Maximum 30 Amps Maximum 26 Amps Maximum 5 Amps Maximum 6 Amps 250V 12.5A 5mmx20mm RLA <= 22 Amps January 11, 2016 10 Revision 1.02
Specifications (CONTINUED) Display and Sensor Cable Flat (oval) multi-conductor shielded modular type cable consisting of stranded tinned copper conductors with thermoplastic insulation and a 22 AWG stranded fused tinned copper drain wire with an overall 100% coverage aluminum/polyester shield in a PVC jacket. Five conductors are used for the sensor cables and seven conductors for display cables with 26 AWG 7/36 strand wire covered with.009in (Nominal) insulation. Adirondack wire and cable type AWC195 or similar type cable. CAN bus wire: Compatibility: SAE J1939 Characteristic impedance: 120 ohms Line capacitance: < 80pF per meter at 1 MHz Wire gauge: 20 AWG minimum Specific line delay (velocity factor) : > 70% Mechanical: 2 conductors, twisted pair with shield and drain connection. Examples of acceptable wire: North Wire Data Cell J1939 Waytec CB20-11F 20 Prestolite Wire SAE1939-15 #149812 COPYRIGHT 2016 Micro Air Corporation, All Rights Reserved No part of this publication may be reproduced, translated, stored in a retrieval system, or transmitted in any form or by any means electronic, mechanical, photocopying, recording or otherwise without prior written consent by Micro Air Corporation. Every precaution has been taken in the preparation of this manual to insure its accuracy. However, Micro Air Corporation assumes no responsibility for errors and omissions. Neither is any liability assumed nor implied for damages resulting from the use or misuse of this product and information contained herein. January 11, 2016 11 Revision 1.02