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).
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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.
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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.