The PowerClamp (PC3 if the 3rd generation of this product) is a device for limiting the maximum output voltage of a PowerSpout hydro turbine, so as to protect sensitive equipment such as charge controllers or grid-tied inverters (GTIs) that are connected to it. It is an external device, wired to the output of the turbine. It uses PWM diversion of current to a heating load as a means to limit the voltage that is passed on. For added security it incorporates an independent fail-safe crowbar that safely short-circuits the turbine's entire output current if the voltage climbs too high.

The primary purpose of the PowerClamp is to allow PowerSpout turbines to operate at a more appropriate (higher) voltage when connected to common MPPT and GTI equipment. Open circuit condition is prevented by the PowerClamp's diversion load, so there is no danger of damage.

Model	Turbine Design Voltage	Minimum Dump Voltage	Initial Dump Voltage	Maximum Dump Voltage	Crowbar Voltage
PC3-140	80-100	50	110	120	140
PC3-250	200	120	210	220	250
PC3-400	300	220	310	350	400
Bespoke	50 to 360	50	x	350	100-400

We recently updated the user manual to reflect theses changes.

This PowerClamp has some new features:

Adjustable dump voltage.
Two aux signals (one PWM and one timer) so you can divert excess power to a useful load before dumping power.
Local web page interface for setting adjustment and monitoring.

This PowerClamp needs to be installed in a suitable area out of the weather.

The air resistor(s) (which come with the PowerClamp) will need to be mounted in a way that:

Protects what the resistors are mounted on from heat
Protects against fingers touching the terminals causing a shock hazard
Protects against rodents entering and nesting close to the resistors
Protects from water ingress/corrosion with a rainproof hood

Please read the detailed specifications and installation guide prior to purchase with your PowerSpout hydro turbine.

Please read our higher voltage applications quide for more detailed information on this topic.

PowerClamps (voltage protection)