Difference between revisions of "Heatweb BEMS Hat"

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[[File:Plumbingcontrollerv3b.png|right|frameless|580x580px]]
[[File:Zccfront3.PNG|right|frameless|703x703px]]
[[Category:Hardware]]
[[Category:Hardware]]
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DIP selected mode<br>
DIP selected mode<br>
100Hz pulse signals<br>
100Hz pulse signals (count and frequency)<br>
volt-free contacts<br>
volt-free contacts<br>
0-10V signals<br>
0-10V signals<br>
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100Hz pulse signals<br>
100Hz pulse signals<br>
volt-free contacts
volt-free contacts<br>
State, counter and frequency readings
|-
|-
|4 x PWM inputs
|4 x PWM inputs
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== About ==
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.
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.


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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.
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.
[[File:Zero Carbon Controller Summary.pdf|none|thumb]]
== Schematic ==
[[File:THERMAL-Controller-V4 0-SCH.pdf|none|thumb]]
== Images ==
<gallery widths="450" heights="300">
File:Plumbingcontrollerv3b.png
File:Heatweb BEMS Assembly V3 + Pi iso3.png
File:Cm4-io-base-a-3.png|Raspberry Pi Compute CM4 Base Board
</gallery><gallery widths="444" heights="333">
File:Heatweb BEMS enclosure assembly4.png
File:Heatweb BEMS enclosure assembly3.png
File:Heatweb BEMS enclosure assembly2.png
File:Heatweb BEMS enclosure assembly1.png
File:Heatweb BEMS enclosure assembly.png
File:Heatweb BEMS enclosure assembly Sectional View.jpg
File:Heatweb BEMS enclosure assembly RC2.png
File:Heatweb BEMS enclosure assembly RC1.png
</gallery>
== Resources ==
* https://github.com/heatweb/plumbing-controller
* https://github.com/SequentMicrosystems/ti-rpi/
* [https://github.com/SequentMicrosystems/ti-rpi/blob/main/MODBUS.md Modbus Registers]
* [https://www.waveshare.com/cm4-io-base-a.htm Waveshare CM4-IO-BASE-A]
* [https://www.waveshare.com/wiki/CM4-IO-BASE-A Waveshare CM4-IO-BASE-A Wiki]
* [[Wiring Diagrams]]
* [[Wiring Editor]]

Latest revision as of 14:10, 7 November 2022

Zccfront3.PNG
Feature Specifcations

Controller compatibility:

Raspberry Pi, all models
Beaglebone Black
ESP32
None (stand alone Modbus Slave Mode)

Controller interface:

Raspberry Pi header
I2C communications to controller
3x UARTs
5V power to controller
External watchdog to controller

8 x thermistor inputs

10k resistance temperature devices

4 x universal inputs

DIP selected mode
100Hz pulse signals (count and frequency)
volt-free contacts
0-10V signals
1k or 10k thermistors

4 x volt-free / pulse inputs

100Hz pulse signals
volt-free contacts
State, counter and frequency readings

4 x PWM inputs

DIP selected pull-up resistors (5V)
Voltage comparator
Low state: < 3V
High state: 3V to 24V

4 x Digital PWM outputs

Pull-down operation
DIP selected pull-up resistors (5V/24V)
Diode protection for connection to relays

4 x 0-10v outputs 10mA peak current
2 x change-over relays 10A @ 36V
2 x RS485

Independent lines for Modbus or bespoke protocols
DIP switch selectable terminating resistors
One line DIP switchable for Modbus Slave Mode

1 x M-Bus

For meter communications
On-board supply: 36V @ 30mA
Short-circuit protection
Device limit: 10

Power Supply

Nominal voltage: 12VDC
Current requirement: 3A
Minimum supply voltage: 11.8V
Peak supply voltage: 16V

Battery support

On-board rechargeable battery socket
Maintains power to all systems (5V, 24V & 36V) during loss of supply
Voltage monitoring with safe shutdown
Duration: > 1 hour (can be extended with use of sleep mode)
Battery: 18650 Lithium-ion Rechargeable Cell - 2500mAh 3.7V 20A

Real time clock Battery:CR2450 Coin Cell
General purpose input button
3 x user definable LEDs
Fan control and connector
Dimensions

Length:
Width:
Height:


About

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.

Zero Carbon Controller Summary.pdf

Schematic

THERMAL-Controller-V4 0-SCH.pdf


Images

Resources