Introduction: DIP switches let an installer set battery voltage, low-voltage cut-off, input voltage range, output priority, and energy saving mode on site without any network connection.
Most off-grid inverter chargers get commissioned in places where a phone signal is a luxury: a telecom hut on a hillside, a farm shed at the end of a dirt road, a container office behind a diesel generator. There is no laptop on the wall and often no app account worth opening. That is exactly why the small switch block on the control board still matters. On the HET Power HS series, that block is where the machine learns which battery bank it is connected to, how low it may drain it, what mains voltage it should accept, and whether the load should run from the grid or from the battery first. this guide walks through those parameters one at a time and explains what each choice does to daily operation.
A DIP switch is a row of tiny two-position switches on the control board or behind the front panel. Each switch is either up or down, and the firmware reads the whole block when the machine powers up. That reading becomes the set of operating rules the unit follows: when to stop discharging, what counts as acceptable mains, whether the output stays awake, and which source feeds the load first. On the HS series, the block covers four parameter categories — battery under-voltage protection point, AC input voltage range, energy saving mode, and output priority. Those four cover most of what makes one off-grid site behave differently from another. Nothing on the list is exotic, but each one changes how the system behaves every day rather than once. The reason this lives in hardware instead of a settings menu is simple: many off-grid sites have no network at all. There is no Wi-Fi router, no 4G coverage, no laptop with a configuration cable. An installation technician sets the block during commissioning, checks the result on the LCD display, and the machine keeps those rules for years. Remote monitoring through RS485, WiFi, or 4G is a separate layer — useful for watching what the system is doing from a distance, but it does not replace the physical selection made on site. Interface standards such as IEEE 802.3k-1992 and ITU-T L. 1200 approach power interfaces the same way: a supply is defined by the operating rules it follows, not only by the connector on the back. The switch block is where an installer declares those rules locally.
Two separate decisions sit in this part of the block, and installers sometimes treat them as one. The first is which battery bank voltage the machine is connected to. The second is how far it may drain that bank before it stops. Getting the first one wrong makes the second one meaningless, because every protection threshold is calculated from the base voltage the machine believes it is running on.
The HS series runs on 12VDC, 24VDC, or 48VDC depending on the model. The smaller units around 1kW to 3kW can be configured for any of the three, the 4kW to 6kW models work with 24V or 48V banks, and the 8kW to 12kW models are built around 48V systems. The numbers move with the voltage: a low-voltage cut-off published as 10.5V at 12V becomes 21V at 24V and 42V at 48V, because the thresholds scale by a factor of two and then four. That scaling is the whole reason the voltage selection has to be correct before anything else is touched. If the machine is told it is on a 24V bank while a 48V bank is wired to the terminals, the protection points land in completely the wrong place — either cutting off far too early or letting the bank run dangerously low.
The low-voltage protection point is the level at which the inverter stops drawing from the battery. Two related thresholds usually matter here: an alarm point that warns the operator, and a cut-off point that actually ends discharge. Choosing between the available settings is a trade-off rather than a fixed rule. A higher cut-off keeps the battery in a shallower discharge band, which generally extends service life but shortens how long the load keeps running. A lower cut-off buys runtime at the cost of deeper cycling and more wear. The right answer depends on the site: a telecom cabinet that recharges every sunny day can afford a more conservative setting, while a farm that might wait three cloudy days before the array catches up may need more runtime and accept the trade-off. IEC 62128-2 treats protection and isolation as their own layer of electrical safety, which is a useful way to think about a cut-off point — it is a protection setting, not a performance preference. The exact positions and which combinations are available for a given model come from the manufacturer's manual.
Output priority decides which source feeds the load when more than one is available. In mains priority, the load runs from the grid whenever the grid is present and inside the accepted voltage window, the charger keeps the battery topped up, and the inverter stays in reserve. This suits sites where the grid is mostly reliable and the battery exists for outages. In battery priority, the battery — usually charged by solar — runs the load first, and the grid steps in only as a fallback or as a charger. That suits sites where grid power is expensive, intermittent, or simply unwanted during daylight hours. Neither setting is better in the abstract. The choice follows what the site is trying to achieve: longest possible backup, lowest grid consumption, or maximum use of the array. Energy saving mode works on a different axis. It reduces the inverter's own idle draw when no meaningful load is connected, which matters on remote sites where the machine runs twenty-four hours a day off a modest array and its own self-consumption is a real part of the daily energy budget. The trade-off is that the output goes into a search pattern and wakes when a load appears, so a very small load can take a moment before it is powered. The AC input voltage range setting sits alongside this logic. The HS series supports a low window of roughly 90–135VAC and a high window of roughly 154–264VAC, and that choice tells the machine when to accept the grid and when to treat it as unusable and switch to battery. On a weak rural feeder that sags every evening, the wider low window keeps the charger working instead of forcing the site onto battery too early. Put together, these settings define the daily rhythm of an off-grid system: how often the battery cycles, how much grid energy gets purchased, and how much backup remains when the grid finally fails for a long stretch. A poor combination shows up as a battery that is drained every night and recharged every morning, or as a site sitting on the grid while a full solar array does nothing useful. Because the choices are physical, they also stay put — which is the point for installations that nobody visits more than once a year.
DIP switches are the local commissioning layer of an off-grid inverter charger, and on the HS series they cover four things an installer actually needs to decide: battery voltage, low-voltage protection, AC input range, and output priority with energy saving. The logic is straightforward once the order is clear — battery voltage first, protection points second, then the operating priorities that shape daily behaviour. Anyone planning a site without reliable network access can review the HS series off-grid low frequency inverter specification to see how those parameter categories map onto 1kW to 12kW models.
A：On the HS series, the DIP switch block covers four parameter categories: the battery under-voltage protection point, the AC input voltage range, energy saving mode, and output priority. Together these control when the machine stops discharging the battery, what mains voltage it accepts, whether it reduces its own idle draw, and whether the grid or the battery feeds the load first. The exact switch positions and the combinations available for each model are listed in the manufacturer's manual rather than guessed on site.
A：Start by confirming the actual bank voltage wired to the terminals, then select the matching voltage setting before anything else. The HS series supports 12VDC, 24VDC, and 48VDC depending on model, and the protection thresholds scale with it — a 10.5V cut-off at 12V becomes 21V at 24V and 42V at 48V. Because every threshold is calculated from that base, a mismatched setting puts the low-voltage protection in the wrong place and can either shorten runtime or over-discharge the bank.
A：Mains priority runs the load from the grid whenever the grid is available and keeps the battery charged for outages, which suits sites with a mostly stable supply. Battery priority runs the load from the battery and solar first, using the grid only as a fallback or charger, which suits expensive or unreliable grid power. Energy saving mode is separate — it lowers the inverter's own idle consumption when no real load is connected, at the cost of a brief wake-up delay for very small loads.
