Hi-Velocity LV-Z Series Air Handlers utilize a WEG Variable Speed Drive CFW300 for fan control and a PSB Circuit Board for zoning. When integrating with Messana Controls, there are two connection methods: 0-10V modulation and Digital Outputs.
Method 1: 0-10V Modulation (preferred)
In this method, the Messana Controls bypass the PSB zoning board, connecting directly to the WEG VSD using a dedicated 0-10V Analog Output (AO) from either an mBox or an mZone module. The terminals are marked as 0V (black) and Y (yellow).
Please follow these steps:
- Disconnect the black and red wires coming from the PSB board that are connected to terminals 7 and 8 on the WEG VSD, and cap them.
- Connect the dedicated AO on the Messana device to the WEG VSD as follows:
- 0V (black) to Terminal 7 (GND, 0V reference)
- Y (red) to Terminal 8 (AI1, 0-10V)
Method 2: Digital Outputs (1, 2, or 3 speeds)
This method requires one or more Digital Outputs (for example, DO1, DO2, and DO3) available on the Messana controller, allowing up to three different speeds.
The Digital Output(s) are connected as follows on the PSB Circuit Board:
- DO1 to R-Y1 (Speed 1 set by the blue Trim Pod marked as Cool)
- DO2 to R-W1 (Speed 2 set by the blue Trim Pod marked as Heat)
- DO3 to R-G (Speed 3 set by the blue Trim Pod marked as Fan)
Connect terminal "R" to the commons
In this configuration, R is the hot leg of the 24VAC transformer. When controlled with dry contacts sharing the same commons, always connect R to the common terminals.
1-speed Control
If you need to control the air handler with just one speed, only use one DO on the Messana controller connected to R-Y1 and adjust the speed by tuning the blue Trim Pod marked as Cool.
CAUTION
Always follow safety protocols when working with electrical equipment. If unsure, consider hiring a professional for installation or modifications.