Multiswitch Power Consumption: What a Satellite System Costs per Year

A multiswitch is one of the few devices in a building that nobody ever switches off. It sits in the service room or under the roof and has been running since the day it was installed. That is exactly why its power draw is worth a closer look: how much electricity does it actually use, what does a standby circuit save over a year, how do you calculate your own installation and which model fits your number of subscribers? We manufacture these multiswitches, so this article uses the same figures we work with ourselves — including the assumptions behind every number.

How much power does a multiswitch use? The short answer

A multiswitch serving eight subscribers draws roughly 5 to 6 watts in operation, but only 0.1 watts once it shuts down — provided it has a standby circuit. The difference sounds small and is not: a device without standby runs at full power around the clock, while a device with standby only runs when somebody is actually watching. Across a building with eight flats, that gap comes to around 37 kilowatt-hours a year.

The SPAUN compact multiswitches of the SMS 07+ series ship with that circuit. It is called Energy Saving Technology, and it switches off more than the amplifier: it also cuts the power supply to the LNBs on the roof, which is the larger share. In standby, the single-satellite models typically draw 0.1 watts and the two-satellite model typically 0.2 watts.

Why a multiswitch draws power around the clock

A multiswitch is not a passive splitter. It makes a decision: every connected receiver requests a specific reception level over its own cable, and the multiswitch routes precisely that level to precisely that output. Doing so requires electronics, and electronics require power.

What the multiswitch has to keep supplied

Three things depend on the power supply. First, the switching matrix that distributes the four reception levels across the subscriber outputs. Second, the amplifier stages that raise the signal level enough to survive 30 metres of cable and several outlets — the SMS 07+ delivers up to 102 dBµV at its outputs. And third, the largest item: the remote power supply for the LNBs.

The data sheet puts the switch's own draw at 10 mA and budgets 38 mA per occupied subscriber output on the 18-volt rail. Eight occupied outputs therefore work out at roughly 5.7 watts. That figure scales with the outputs actually in use, not with the outputs available: a sixteen-way unit serving four receivers uses considerably less than one serving all sixteen.

Why LNB remote power is the biggest item

The LNB on the dish has no mains socket of its own. It receives its operating voltage through the same coaxial cable it sends the signal back on — 13 volts for one polarisation plane, 18 volts for the other. The multiswitch provides that supply, simultaneously, for every connected LNB output. On the SMS 07+ series, up to 500 mA in total is available for this.

This is where economical and uneconomical devices part ways. A multiswitch without shutdown logic maintains that supply even when no receiver has been running for hours. It powers an LNB whose signal nobody is watching.

Does it keep drawing power when every television is off?

On a device without a standby circuit, yes. It has no way of knowing whether anyone is watching, so it stays in full operating mode permanently. On a device with a standby circuit, no. As soon as the last receiver stops applying supply voltage to its cable — meaning it is genuinely off, not just the television in front of it — the multiswitch powers down.

That distinction matters for your own calculation. What counts is not how long the television runs, but how long at least one receiver is switched on or recording.

What the standby circuit saves — the calculation

Work it through yourself. Every input value comes from the SMS 07+ data sheet, and every assumption is stated so you can replace it with your own.

How to calculate your installation's consumption

The formula has three steps. First, power in operation: number of occupied outputs times 38 mA, plus 10 mA for the switch, all multiplied by 18 volts. Second, operating hours: how many hours a day is at least one receiver active? Third, the rest of the day at the standby figure. Together these give the daily consumption; times 365 the annual consumption; times your electricity price the annual cost.

One note on accuracy: this calculation happens on the secondary side, behind the power supply unit. Losses in the power supply itself are not included, so the actual draw at the wall socket is somewhat higher. For comparing two devices that makes no difference — both sides of the comparison are affected equally.

Worked example: eight flats on one multiswitch

The assumptions are eight occupied subscriber outputs, six hours a day with at least one receiver running, and an electricity price of 35 cents per kilowatt-hour. These are assumptions, not measurements — your installation may differ.

The figures are rounded. If you record a lot and your receivers are therefore active for longer, both columns move up — but the gap between them remains as long as there are hours in the day when nobody is watching.

What a device without a standby circuit costs extra each year

Around €13 a year for an eight-subscriber multiswitch, around €130 over a typical service life of ten years. That is the order of magnitude in which the premium for a branded device pays for itself after a few years — which is precisely why we build the standby circuit into the entire series rather than only into the larger models.

Two qualifications, so the number is not read as larger than it is. First, the effect scales with the installation: with six subscribers it is smaller, with sixteen it is noticeably larger. Second, the multiswitch is not the only device running permanently — the receivers count too, and they count once per flat.

Energy Saving Technology: how the shutdown works

The name is on the data sheet; behind it sits a simple, robust piece of logic with no timer, no app and nothing to configure.

When does the multiswitch shut down — and when does it wake up?

The multiswitch listens for the supply voltage each receiver applies to its cable. If no subscriber output carries voltage any more, it switches off the SAT-IF amplifier stages and the LNB remote power supply and enters standby. As soon as any receiver — or a signal meter during installation — applies voltage again, it returns to normal operation automatically.

So there is nothing to set and nothing to forget. The circuit works purely from the state of the connected devices.

Two satellites, two decisions: selective shutdown

The two-satellite model, the SMS 9807+ NF, adds a second stage. It checks not only whether anyone is watching at all, but also whether the second LNB is currently needed. If nobody is watching the second satellite position, that LNB stays unpowered while the first position keeps running.

This is why that model has a slightly higher standby figure: typically 0.2 watts instead of 0.1, because two branches are monitored instead of one. In operation the selectivity pays for itself daily, since a second satellite is used far less often than the first in most households.

Will you notice anything as a viewer?

A receiver needs a moment to build the picture after being switched on anyway, and the multiswitch is active again long before that. The same applies to scheduled recordings: a receiver waking up at its programmed time applies supply voltage and thereby brings the multiswitch back into operation itself.

Built-in switch-mode supply or external plug-in adapter?

The second lever on consumption is the type of power supply. The SMS 07+ series has a switch-mode power supply inside the unit, rated for 90 to 240 volts at 47 to 63 hertz and short-circuit proof.

Why a plug-in adapter keeps counting

An external power supply sits in the socket and converts for as long as it is plugged in. It has no connection to the multiswitch's shutdown logic and therefore cannot benefit from it. A built-in supply, by contrast, is part of the same circuit: when the multiswitch enters standby, the draw of the complete device falls to the stated figure — power supply included, because it is the same device.

There is a practical point as well: one component fewer in the cabinet means one plug connection fewer that can work loose, and no adapter block to find space for in the distribution box.

Short-circuit proof — what that means in practice

During installation an F-connector occasionally fails to seat cleanly and a strand of the shield touches the centre conductor. A short-circuit-proof power supply limits the current in that case instead of taking damage; once the connector is redone, the unit carries on normally. On an installation with eight or sixteen cables being terminated one after another, that is a sensible reserve.

How to measure what your installation really draws

The calculation above is a model. If you want to know for certain, measure — it takes an evening and costs nothing beyond a meter for about €15.

Measuring with a plug-in energy meter

Put a plug-in energy meter between the socket and the multiswitch. Note the reading once while a receiver is running, and once after every receiver has been off for at least a minute. Those two figures are your real operating and standby power, measured at the socket and therefore including power supply losses.

Better still: leave the meter in place for a full week and read the kilowatt-hours. Multiplied by 52, that is your installation's annual consumption without any assumption about usage hours.

What the electricity meter can tell you

If you have no plug-in meter, use the electricity meter itself: note the reading, switch off every known load, wait an hour and read it again. The difference is your household base load. If a noticeable share of it disappears when you briefly disconnect the multiswitch, you have your answer. On a device with a working standby circuit, the difference should be barely measurable.

Which SPAUN multiswitch fits your installation?

Every model in the SMS 07+ series shares the same technology and differs in the number of subscribers and satellite positions. Development and production take place in Germany.

One satellite: 6, 8, 12 or 16 subscribers

For receiving a single satellite position — Astra 19.2° East in most of Central Europe — the models with one trunk line group are sufficient. They take the four reception levels of a quattro LNB and distribute them across 6, 8, 12 or 16 outputs. Thanks to the built-in 22 kHz generator they also work with a quad LNB; a quattro LNB is recommended, because the multiswitch then only has to distribute.

Two satellites: Astra and Hotbird for eight subscribers

If you also want a second position, for example Hotbird 13° East for Italian, Turkish or Arabic channels, the SMS 9807+ NF is the model to choose. It handles two quattro LNBs and distributes both positions across eight subscribers, who can then switch freely between satellites. Selective shutdown ensures the second position only costs power when it is actually in use.

How many outputs do you really need?

Count tuners, not flats and not televisions. A receiver with a twin tuner, able to record one channel while showing another, occupies two outputs. A television with a built-in satellite tuner occupies one. Add up what is connected today and allow two outputs of headroom — moving from the eight-way to the twelve-way unit costs less once than retrofitting with new cabling later. The full range is in the Multiswitch category.

Reducing consumption: what actually works

• Switch receivers fully off – a receiver in standby often keeps applying supply voltage and thereby keeps the multiswitch running. Only once it is genuinely off can the standby circuit take effect.
• Terminate unused outputs – unused subscriber lines should carry a terminating resistor. This improves the level conditions and stops lines being supplied unnecessarily.
• Use a quattro rather than a quad LNB – on a multiswitch the quattro LNB is the more economical option, because the multiswitch then does not have to generate a control signal.
• Match the size to the tuner count – a sixteen-way unit serving four receivers does not cost much more in electricity, but the purchase price is unnecessary. Conversely, a unit that is too small forces a second purchase later.
• Only add an amplifier where level is missing – an additional inline amplifier is another permanent load. On cable runs that the SMS 07+ covers with its output level of up to 102 dBµV, it is usually unnecessary.
• Measure instead of estimating – a plug-in energy meter answers in a week what any rule of thumb only approximates.

Frequently asked questions about multiswitch power consumption

How much electricity does a multiswitch use per year?

With eight occupied outputs and six hours of daily use, around 13 kilowatt-hours a year if the device has a standby circuit — about €4.60 at 35 cents per kilowatt-hour. Without a standby circuit it is around 50 kilowatt-hours, or about €17.50.

Can I simply switch the multiswitch off overnight?

Technically yes, but on a device with a standby circuit there is little point: it already powers down by itself once the last receiver is off. A timer would additionally prevent scheduled overnight recordings from working, and draws power itself.

Does a 16-output multiswitch use more than a 6-output one?

Only if more outputs are occupied. The data sheet budgets 38 mA per subscriber output in use; unoccupied outputs barely register. Unit size alone does not determine consumption — the number of connected tuners does.

Why does the two-satellite model have a higher standby figure?

Because it monitors two branches instead of one. It checks separately whether the first and the second satellite position are needed and powers the LNBs individually. That costs 0.1 watts more in standby and saves, in operation, powering an LNB nobody is using.

Does the multiswitch need a separate power supply?

Not in the SMS 07+ series — the switch-mode supply is built in and rated for 90 to 240 volts at 47 to 63 hertz. A socket near the mounting position is all that is required.

How can I tell whether my old multiswitch has a standby circuit?

Most reliably with a plug-in energy meter: if the power draw falls well below one watt once every receiver is off, shutdown logic is present. If the figure stays constant, the device runs at full power continuously. On a data sheet, look for entries such as standby consumption or power draw in standby mode.

Is it worth replacing a multiswitch that still works?

Your own figures in the calculation above will answer that. As a guide: with eight subscribers and an older unit without shutdown logic, the saving is in the order of €13 a year. If you are extending the installation or rebuilding the distribution cabinet anyway, that is the moment when the swap costs the least effort.

Ready to pick the right multiswitch for your subscriber count? The complete series with all five sizes is in the Multiswitch category.