Odyssey Symbio Pairing or Twinning Frequently Asked Questions
- Odyssey Pairing or Twinning Limitations and Guidelines
Tech support has had many requests and questions on what kind of equipment can be paired when dealing with Odyssey. There are a few pairings that can cause many difficulties in the field. This document mainly focuses on the issues that arise with the controls wiring and sequence of operation when using Odyssey Symbio products. Refrigerant piping questions should consult the Odyssey piping application guide. Duct design including backdraft dampers for dual air handlers should follow local codes and regulations and follow best practices to prevent excessive external static pressures that may cause air flow issues.
- Can you twin two air handlers with one condenser?
Pairings that have two air handlers with one dual condenser have caused many issues. If the air handlers are serving two different areas, different heat loads, and/or different thermostats, Symbio controls will not allow this type of application. On legacy and some Reliatel condenser units, you could bring on each circuit independently with a Y1 or Y2. On Symbio controls, however, Y1 or Y2 will bring on the first available stage of cooling (usually this is circuit 1). Of course, this is an issue if you would like to use Y2 to bring on circuit 2 independently. This pairing is not recommended and is not supported.
In some cases where you have two equal size air handlers paralleled in the duct serving the same area with the same thermostat or control, you may could pair the air handlers to one condenser. This type of pairing will require field provided relays to isolate any transformer voltages between the different systems. If you are using a single circuit condenser and manifolding the refrigerant piping from the evaporator coils, you must take care ensure proper oil return to the compressor(s). See the latest Odyssey piping application guide for more information.
The use of Symbio heat pump condensers should be avoided with this application due to issues with electric heat operation in defrost. This is explained more later in this document.
- Can you twin two condensers with one air handler?
Under no circumstances can two condenser units have the refrigerant piping manifolded together with one air handler. There is no way to ensure the oil from one compressor will not end up in the other compressor causing eventual and repeat failures.
Two residential condensers can usually be paired with an Odyssey, dual circuit air handler without too much difficulty. The 5 ton Odyssey air handler units already have a transformer installed in them, but any other air handler will need a transformer kit installed. It is recommended an Odyssey TWE 2 Stage Airflow - Symbio use w/ EM, Digit 15 = C be utilized for this application. Again, isolation relays will be needed whenever there are multiple transformers used in the system.
- Can a Symbio Heat Pump be Paired with any unit?
Symbio heat pumps require an Options board to utilize electric heat in defrost mode while in heat pump mode. Pairing this condenser with legacy air handlers can cause operational issues. The unit will not bring on auxiliary electric heat while in defrost, therefore, the system will be discharging cold air for a short period in the space. In some applications, this may be acceptable but can cause a dump of cold air on some of the occupants while the unit is supposed to be heating.
- Can I pair an Odyssey TWE060 air handler with a residential 5 Ton Condenser?
Yes, you can pair these together. The air handler already has a transformer installed for this type of combination to power the system.
- When do I need Communication wire for Symbio?
Communication wire is required for Odyssey Symbio unit when an Options module(s) and/or a VFD setup up for communication is in the air handler. The IMC (intermodule communication) communication allows the Symbio 700 in the condenser to communicate with any Indoor Options Module or Fresh Air Options Module that may be in the air handler. Modbus communication is required for the Symbio 700 to communicate directly to the VFD.
Any SZVAV air handler with the model number 15th digit "D" will need both comm wires ran between the air hander and condenser because it comes with a communication VFD and Indoor Options Module standard from the factory.