Small wind / Buyer questions
Electrical configuration
Can I select a wind controller by its amp rating alone?
The short answer
No. An amp rating must be tied to a circuit, voltage range and operating duty. It could describe a battery-side current, an input current or a diversion-load limit, each with different implications. The controller must also support the generator behavior and required protection arrangement. Matching a turbine's nominal kW with a simple volts-times-amps calculation is a screening step, not a complete compatibility assessment.
The same current can describe very different power
Ideal DC arithmetic: 100 A at 48 V corresponds to 4.8 kW, whereas 100 A at 400 V corresponds to 40 kW. That comparison illustrates why an isolated “100 A” label is incomplete. It does not imply that a 100 A controller rated for one voltage can operate at the other.
Battery voltage also changes through its operating range. Conversion losses, current ripple and temperature can affect the actual equipment duty.
Read the current limit in context
| Question | Why it changes the selection |
|---|---|
| Which circuit? | Input, battery and diversion currents serve different functions |
| Continuous or temporary? | A surge number cannot replace a continuous-duty limit |
| At what conditions? | Voltage, cooling and temperature define the rating |
| Which control mode? | A solar-only input or load-control function may not accept wind |
Compare the complete function
Request accepted source characteristics, input and output ranges, loading-control responsibilities and behavior when the receiving circuit cannot accept energy. Any extra protective equipment must be identified in the supply scope.
MARSTON controllers can be supplied separately, but their suitability for retained equipment is assessed using the actual generator and system information. A familiar amp label from an older controller is not sufficient evidence for a replacement order.
Separate charging and diversion limits
A current limit for supplying a battery may differ from the limit of a diversion path. A controller can also support different functions in mutually exclusive modes. Ask for the limits of the selected mode and each circuit involved. Do not add ratings from separate catalogue rows as though the equipment could perform all of them simultaneously.
Sources
- Morningstar: diversion-control principles
- Morningstar: wind charging and input-protection considerations
Examples are illustrative. Confirm product-specific performance, compatibility and supply scope in the applicable documents.