VCU2-24 Environmental Controller
The VCU 2-24 is a single-zone environmental controller that coordinates greenhouse/high-tunnel ventilation, heating, and cooling in one unit. It supplies 24VDC power for up to two low-voltage curtain motors and includes two dry contacts for heaters or fan/louver contactor boxes. Programming is done via a 3-button LED interface on the door.
Key Features & Capabilities
Sensor Failure Fail-Safe: If the sensor fails, the unit operates from a user-defined override temperature while displaying a fault code.
Heater/Ventilation Interlock: Enforces a minimum gap (adjustable up to 20°) between heating and cooling setpoints to prevent heating against open vents.
Incremental Curtain Cycling: Drives curtain motors for set seconds, idles for set minutes to read temperature, then adjusts. Prevents temperature overshoot and cold shock.
High/Low Temp Alarms: Independent high/low setpoints drive a dry contact (NO or NC) for external autodialers or alarm systems.
Humidity Override (Requires Optional Sensor): Vents and runs fans to lower humidity for disease control, with a low-temperature lockout floor to protect crops from chilling.
Resettable Protection: Features resettable manual protections: 2 circuit breakers, 1 main fuse, and 2 motor fuses.
Output Configurations
Curtains: 2 terminals always available (24VDC, 1 setpoint).
Dry Contacts (#3 & #4): Max 2 outputs total.
| Alarm State | Contact #3 | Contact #4 | Total Outputs |
| Disabled | Heater #1 OR Fan/Louver #1 | Heater #2 OR Fan/Louver #2 | 2 Outputs |
| Enabled | Heater #1 OR Fan/Louver #1 | Dedicated Temp Alarm | 1 Heat/Cool + 1 Alarm |
Note: 2 heaters + 2 fans is not supported. AC fans/louvers require an external AC contactor box. Heaters use a 24VAC signal and independent power.
Components & Accessories
Included: Controller in waterproof latching enclosure, 100′ temperature sensor, mounting brackets, manual.
Required (Sold Separately):
Low-voltage curtain motors (LVM60 or LVM100).
AC contactor box (42-CIBAC-1F1L, 42-CIBAC-2F2L, 42-CB2, or 42-CB4) for fans/louvers.
Optional:
Aspirated humidity sensor (46-HUMID).
150′ temperature sensor (46-TS150) — Sensor wire cannot be spliced; use 150' if 100' is insufficient.
Specifications
Part #: 41-VCU2-24
Input Voltage / Max Amps: 110–240 VAC / 5A
Output: 24VDC / 300W (Supports 2 × 100Nm motors)
Protection: 5A breaker, 10A breaker, 10A main fuse, 2 × 5A motor fuses (All resettable)
Operating Temp: -25°C to 70°C
Dimensions / Enclosure: 13″ × 9.5″ × 6.5″ | Waterproof chassis-mount
Adjustable Settings
Ventilation: Curtain setpoint, motor run time (sec), idle time (min), cooling differential.
Heating/Cooling: Independent setpoints, heater hysteresis / fan differential.
Humidity: Override RH%, run time, fan override RH%, deadspan, low-temp lockout.
Alarm: High/low setpoints, NO/NC relay state.
System/Config: Manual override (latching vs. hold-to-run), °F/°C scale, sensor fail override temp, interlock band width.
Installation Notes
Mounting: Indoors, dry location. Bottom cable entries only (drilling top/sides voids warranty).
Sensor Placement: Center of structure at crop height. Maintain ≥1 ft clearance from high-voltage wiring; cross power lines at 90°.
Electrical: Must be installed by a licensed electrician. Heater and fan power run independently — do not wire power directly to controller terminals.
Prop 65 Warning: Product contains chemicals known to the State of California to cause cancer and reproductive harm.
