The Hoffman Controls 906-VMA Thermostat wall sensor is designed to put out one output signal, 2-10 VDC, and is available in standard size, horizontal, and comes in the range of 50-90F.
This Thermostat Series is designed to provide two output signals 2-10 VDC and 4-20 mA. Both signals are proportional over a 2 F span. The thermostat has an automatic or manual changeover mode that allows the thermostat to function in a Direct Acting (cooling) or Reverse Acting (heating) mode.
The thermostat’s output signal is derived from a precision LM34 IC that produces a linear DC output in millivolts. A direct reading of the thermostat’s sensor output will provide a mV signal. When converted to F, it will indicate the actual temperature sensed; i.e. 768mV = 76.8F. A factory “zero calibration” procedure normalizes all tolerances of sensor and circuit, providing a precise temperature. The thermostat range is 50-90F in one degree F markings.
A system “ON OFF OS” switch is standard. The Direct or reversing function can be selected by the installer as would be required for the application. This could be manually determined by a remote switch closure, or automatically determined by an aquastat in the air distribution system, or by the heating or cooling medium. The accessory aquastat (P/N 510-0075-002), closes at temperatures above 88F and opens at temperatures below 68F. The aquastat is used to indicate the temperature of the fluid that is available in the coil (heat exchanger). Switch closure programs the thermostat for Reverse Acting (heating) while switched open provides a Direct Acting (cooling) function. The 906-Vma thermostat mounts horizontally to a 2×4 J Box.
(Standard, Horizontal, VMA, 50-90F, 2-10 VDC/4-20mA, Wall Sensor, On/Off Offset)
Hoffman Controls 906-VMA Features:
- Proportional control signal
- Responsive time constant
- Wall or remote temperature sensing
Hoffman Controls 906-VMA Application:
The 906-Vma Series Thermostats can be used with any HCC control or EMS output controller that accepts a 2-10 VDC or 4-20 mA input signal. It may also be used to provide either of these two output signals for any other device or control that accepts these specific proportional inputs. The on-off switch can be used to turn “on” or “off” an external device like the 709 motor speed control.
Hoffman Controls 906-VMA Specifications:
- Series – 906 Vma
- Power – 24 VAC
- Min/Max – 20-30 VAC
- VA – 4.0
- Span – 2F
- Output Signals – 2-10 VDC & 4-20 mA
- Set Point Range – 50F-90F
- Sensor Output – mV
- mV to F Conversion – 10mV = 1F
- Accuracy – +/- 0.5F
- Standard Features:
- System Switch – On/Off/Offset
- Mode – Direct (Cool) or Reverse (heat) Acting
- Changeover – Fixed Local or Auto Remote
- Optional Features/Accessories:
- P/N 510-0075-002 – N.C. @ 88F – N.O. @ 68F