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The PowerClamp device is designed to manage excess power from a hydro turbine to maintain optimal turbine loading. By diverting unneeded power, it helps prevent turbine runaway, which can lead to dangerously high voltages and excessive wear on mechanical components.
For Extra Low Voltage (ELV) systems (below 120V), the PowerClamp ensures compliance with ELV electrical codes by preventing voltage from exceeding safe thresholds. It achieves this by using primary dump resistors to dissipate surplus energy safely. Select the PC3-140
Beyond simple dissipation, the device also features outputs to control alternative diversion loads, allowing energy to be used more effectively rather than wasted. These loads can include hot water systems, heat pumps, or other resistive loads that can benefit from excess power.
Operating range 50v - 400v (not diversion range)
Maximum crowbar protection circuit: 40A
Maximum diversion current: 30A
Maximum current per switched load: 10A

Main diversion is 500 Hz PWM and Auxiliary 300 Hz PWM
Crowbar accuracy +-2% separate analog circuit.
|
Minimum Dump Voltage |
Initial Dump Voltage |
Maximum Dump Voltage |
Crowbar Voltage |
|
50 |
110 |
120 |
140 |
|
120 |
210 |
220 |
250 |
|
220 |
310 |
350 |
400 |
There is also a non powerspout turbine models that will work on other turbines and windmills. They allow another resistor in the crowbar circuit to manage short circuit over current.
Connection diagram.

The crowbar will short the turbine in the event the max voltage is reached, eg 140v, 250v or 400v.
The matching resistors for the dump loads called R1, R2, R3,R4 are critical and work in a range of voltages and power ranges, see the graphs for accurate diversion characteristics with correct number of resistors required. Note that you can divert at a lower voltage and as the system produces more power to divert, the voltage will naturally rise to match generation.



Hot water element resistors: The powerclamp is also designed to work standard hot water element resistors, you will still need the same number of elements as resistors, and do not use other wattage elements.
110v AC 1000w elements are ~12.1 Ohm and work with the PC3-140 model
230v AC 1000w elements are ~52.9 Ohm and work with the PC3-250 model
We recommend powering up the device on the bench from either a power supply ~50v eg connect to the a standard 48v battery, use the turbine input to power on and familiarize your self with the console and settings etc.
Set the diversion main dump voltage voltage and the SSID name if you will have multiple Powerclamps. Leave the auxiliary output settings as default until you have confirmed the device is working as expected with the dump resistors.
How to configure the device:
For sites with multiple power clamps on one site, we suggest setting each one up at a time and changing the SSID of each with a unique name e.g. powerclamp1, powerclamp2 etc, then clearly label each one.
If for reason you cannot remember your password etc, there is a button on the circuit board to reset everything to factory default. This includes the calibration.
Calibration: The device is sometimes a few volts out, therefore always calibrate after a factory reset, we suggest having a very stable conditions eg DeltaV <2 and then enter the voltage on the PCE in the settings page. It will display the voltage it is reading, this should now match your PCE going forward.
The PowerClamp provides multiple methods for managing diversion loads:
Timer-Based Switching: Outputs can be configured with preset minimum on and off times to prevent excessive cycling, improving efficiency and prolonging equipment life.
PWM (Pulse Width Modulation) Control: Where applicable, the device can modulate power output smoothly rather than switching fully on or off, offering finer control over diversion loads.
The auxiliary diversion voltage should always be set below the main diversion dump voltage to ensure proper operation and priority handling.
A 15-second fixed delay is implemented before the timer changes state. The condition must be continuously met for 15 seconds before the output switches on or off.
Unused auxiliary settings should be left at their default (high) to prevent interference with the front light indicator, avoiding confusion about the PowerClamp’s operation.
Wired Outputs: The device features two direct-wired auxiliary outputs for local diversion control.
LoRa Wireless Outputs (Upcoming Feature): An additional two outputs are planned for future production, allowing remote load control via LoRa wireless communication.
To ensure stable operation we recommend:
Any single Auxiliary load should be up to ~1000 watts but in some cases no more than the maximum output of your generation.
Example 140V model: Voltage diversion = 110, Aux1 = 105, Aux2 = 100
Example 250V model: Voltage diversion = 210, Aux1 = 200, Aux2 = 190
For support on possible options please contact your supplier or powerspout directly for support.
The PWM signal is at 300 Hz and can be used for switching DC loads from the battery directly.
If the PCE fails then the Powerclamp will see that there is excess power and switch on the diversions, if the auxiliary diversions are in use, they will drain the battery, therefore please connect the battery as an input and set the lower voltage cut off, this will switch off the auxiliary diversions and preventing the main battery's being drained. The powerclamp will divert to the main dump resistors until the PCE has been repaired.
On version 3.0.2 and above there are LED's on the front to indicate what it is doing.
Green = power on
Red = Diverting some power the resistor bank.
Yellow = Diverting some power to an Auxiliary port.
Blue = reserved for LORA status.
When multiple devices are used, once connected there is a "Find Me" button which triggers the display to flicker for 10s, this will allow you to confirm which physical device you are connected to.
Can I use a tablet or old phone permanently connected and mounted on the wall beside the powerclamp?
Yes, this has worked well, set the device to auto reconnect to the WIFI, and set the 192.168.4.1 as the home page. Connect to a USB power supply permanently, set power settings to stay on when on charge.
Once connected to 192.168.4.1 you will receive the Data page, Which is a real time graph of current voltage and diversion to resistors, full scale is fully on to that resistor dump load etc.
Plus some key operating information at the bottom.
What is Delta?
Delta: this is the voltage fluctuation of the incoming turbine voltage over a 4 s period. As the powerclamp diverts power to the resistors this is an indication of how stable it is. It will spike as things change such as a sudden need for diversion etc but under stable conditions this should be less than 5% of the current voltage. This is mainly used for diagnostics for unexpected crowbar triggers. This also gives an indication on how close you can set the divert voltage to the crowbar voltage.
We will release updated firmware which may either resolve an issue or add features.
Please check your current version found on the settings page.
To update the powerclamp, download the two files, firmware and filesystem .bin files or the ZIP file and extract the two prior, Connect to the powerclamp through wifi and upload, update the firmware first and then complete the filesystem, you may need to manually reconnect to the wifi in between.
Ensure the powerclamp is on a stable power supply >50v and not diverting. Although I have done this and it worked ok, I would not suggest it.
If there is an issue uploading the filesystem and you cannot reach the web interface to reupload, on firmware prio to 3.0.9.3 manually go to Firmware update page http://192.168.4.1/update
Firmware change log
Firmware 3.0.8
New Features & Improvements
Voltage readings now displayed to 1 decimal place.
Over-the-Air (OTA) update page added for easier firmware updates.
Added option to download text summary of all settings for support.
New controls to set Wi-Fi channel and Wi-Fi power level (for high-density installs, e.g. >3 Powerclamp's in one room).
System now calculates estimated diversion watts, with configurable resistor value and number of resistors.
Diversion algorithm updated with adjustable parameters:
Attack speed
Release speed
Knee sensitivity
Firmware 3.0.9.3
New Features & Improvements
Firmware 3.0.10.0
New Features & Improvements
The version number do not always increment as the ones in between are none stable releases and were used internaly only for testing.
Dealers only: The crowbar part is separate from the powerclamp controller, and each device can be configured for any mix of models, eg powerclamp can operate just below the 140V region using a 15 Ohm resistors and the crowbar can be set to 140v, 250v or 400v independently. both are set by a solder join marked on the PCB.