Difference between revisions of "Heatweb BEMS Hat"
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Maintains power to all systems (5V, 24V & 36V) during loss of supply<br> | Maintains power to all systems (5V, 24V & 36V) during loss of supply<br> | ||
Voltage monitoring with safe shutdown<br> | Voltage monitoring with safe shutdown<br> | ||
Duration: > 1 hour | Duration: > 1 hour (can be extended with use of sleep mode) | ||
|- | |- | ||
|Real time clock | |Real time clock | ||
Revision as of 17:49, 4 October 2022
| Feature | Specifcations |
|---|---|
| 8 x thermistor inputs |
10k resistance temperature devices |
| 4 x universal inputs |
100Hz pulse signals |
| 4 x volt-free / pulse inputs |
100Hz pulse signals |
| 2 x change-over relays | 10A @ 36V |
| 4 x PWM inputs |
DIP selected pull-up resistors (5V) |
| 4 x PWM outputs | DIP selected pull-up resistors (5V/24V) |
| 4 x 0-10v outputs | 10mA peak current |
| 2 x RS485 |
Independent lines for Modbus or bespoke protocols |
| 1 x M-Bus |
For meter communications |
| Power Supply |
Nominal voltage: 12VDC |
| Battery support |
On-board rechargeable battery socket |
| Real time clock | |
| General purpose input button | |
| 3 x user definable LEDs | |
| Fan control and connector |
The Heatweb BEMS Hat runs from a 12v dc supply, generating 5v for the board, 24v for valves, and 36v for M-Bus, using on-board dc-dc converters backed up by a rechargeable battery. A coin cell is used to power a real-time clock.
WiFi, Ethernet and Bluetooth are provided by the parent controller board.
A number of the inputs are universal, and can be switched between NTC, 0-10v, or volt-free / pulse inputs (jumper selected). This ability to alter the hardware setup increases versatility significantly.
The addition of M-Bus allows us to connect to heat meters as standard, making the board a stand alone solution to open-sourcing meter data, and to use meter data within control logic.
The battery backup allows us to safely shut-down all valves and the controls when power is removed. This overcomes a common problem with HVAC systems, where valves typically remain open, destroying network performance.