A closed water system does not work without electricity, since the pump circulates the coolant. Heating units with microprocessor control units are also powered by the mains. Hence the conclusion: it is advisable for the owner of a private house to acquire an uninterruptible power supply (abbreviated as UPS) in case of an emergency power outage. We will show you how to choose a UPS for a heating boiler of any type - gas, solid fuel, pellet or diesel.
3 power supply selection criteria
Let's start with the statement of the problem. When the light is turned off, the “uninterruptible” for the boiler must immediately assume the function of an external power source and support the operation of heating equipment until the power supply resumes.
Simplified, the principle of operation of the UPS looks like this: in normal mode, the unit converts alternating current into direct current and charges the battery. When the voltage disappears, the reverse process occurs - the direct current of the battery is converted into alternating current, which is supplied to the boiler.
Several types of backup power devices are sold in online stores, the price of units varies over a wide range. To choose the right UPS without unnecessary overpayments, consider 3 factors:
- power consumption of the boiler and other equipment - additional pumps, fans, electric drives on mixing valves, temperature controllers;
- battery life;
- power quality in the area of residence.
Note. Poor-quality power supply means frequent blackouts, severe voltage drops in the network or the use of a gasoline generator.
Now we will analyze the listed factors in more detail.
How to determine the power of the UPS
Since in all modern heating systems from 1 to 10 circulation pumps are involved, the “uninterruptible” is required to withstand high inrush currents. At the moment of switching on the unit, this indicator increases at least 2 times (on more powerful pumps of the water supply system - 3 times). We consider the power of the power supply as follows:
- We find out the energy consumption of each piece of equipment - a boiler, free-standing circulation pumps, fans or smoke exhausters of a TT-boiler, electric drives, pellet / diesel burners.
- Summarize the data, multiply the result by 2.
- We select a UPS whose capacity is equal to or greater than the received figure.
If you approach scrupulously, you would only need to double the power of the pump and fan motors, because the electronics do not create inrush currents. But the share of electronic systems in total energy consumption is so small that there is no sense in counting it separately.
Reference. The power consumption of the gas wall-mounted boiler is specified in the unit passport or on a plate attached to the housing. For most pumps, the parameter is indicated on the end, next to the screw, as shown in the photo below.
Example. Gas boiler installation consumes 130 watts, an additional pumping unit - 82 watts. The minimum power of the uninterruptible power supply will be (130 + 82) x 2 = 424 watts.
Duration of work
How long the gas boiler from the UPS will last will be determined by the homeowner from personal experience. Only you know the duration of power outages in the place of residence. Based on these data, choose 1 of 2 types of “uninterruptible”:
- When the light disappears for 10-15 minutes, it is enough to have a unit with a built-in battery. If the shutdown is delayed for 30-60 minutes, you can correctly complete the operation of any heat generator - gas or solid fuel.There will still be a margin for cooling the building, a feeling of cold will appear in 1–1.5 hours.
- For longer power outages, you will need a UPS with an external battery. Please note: usually the battery is not sold complete with the device, it will have to be bought separately.
Tip. If there is no electricity for days, an “uninterruptible” with batteries will be too expensive. Cheaper to buy a gasoline generator + voltage regulator. A more cardinal way is to mount gravity heating with a non-volatile gas / wood boiler.
As you might guess, the duration of heating depends on 1 indicator - the battery capacity, the power of the unit does not play a role. For example, a UPS with an external battery of 60 ampere-hours will be able to support our heat generator with a pump (212 W) for 2 hours. Take a 75 Ah battery and get about 3 hours of working time.
It is quite difficult to clearly calculate the duration of the boiler from the “uninterruptible” with the battery. The reason is erratic energy consumption:
- the gas heating unit periodically stops and ignites the main burner;
- the automation of the TT boiler controls the fan, purges the furnace, and sometimes turns off the pump;
- in a pellet burner there are 2 engines (auger and supercharger) plus an automatic ignition element, the listed equipment is controlled by the controller.
To choose the capacity of the battery, we suggest using the table, it indicates the approximate battery life, depending on power consumption and charge size. When choosing, make a margin of 10 ... 20% for the starting currents of electric motors.
Power Quality
Before choosing a UPS for a gas boiler or another type of heat generator, measure the voltage drops in the house electrical network. The problem is this: far from every “uninterruptible” can function normally when falling below 180 volts. In such cases, 2 scenarios are observed (depending on the model of the device):
- The device gives a signal about the absence of current and begins to take energy from the battery, although in reality the light did not turn off. The battery runs out quickly, the resource is reduced.
- The UPS simply shuts off, showing an error and beeping. Next, the heat generator stops along with other equipment.
Conclusion. In the presence of deep drawdowns of the mains voltage, you should choose a UPS with a built-in inverter stabilizer capable of equalizing drops in the range of 140 ... 300 volts. If you have already purchased a regular “uninterruptible”, you will have to buy a separate stabilizer.
The requirement also applies to gasoline / diesel generators. These units poorly support the current frequency of 50 Hz (excluding expensive modifications), that is, they give the wrong sine wave at the output. The generator is connected to the boiler through a UPS with an inverter stabilizer and a separate automatic start device (ABP unit). The power plant should start itself - suddenly the owners will not be at home when the lights are turned off.
How to choose a UPS for a gas boiler
When we found out the power consumption, the amount of battery charge and how to equalize the voltage, we can proceed to the choice of the “uninterruptible” itself. Online stores offer power supplies with 3 types of architecture:
- off line devices;
- line-interactive UPS;
- on-line continuous blocks.
The principle of operation of offline “bezerebybonika” is simple - what voltage enters the block, this goes. If the network drops dramatically, the device uses battery power. The online device works differently: first, the input current is rectified, “driven” into a strict framework - 220 ... 230 V, 50 Hz, then it is again converted into a variable and sent to the consumer. The line-interactive UPS is an off line unit with a built-in stabilizer.
Reference.The cost of “uninterruptible” depends on the architecture, power and input voltage range. Example: a Chinese UPS “Luxeon” (0.3 Luxe) type online costs about 60 y. e., a similar interactive - 100 at. e. If you need power of 700 watts, then the cost increases to 210 and 160 at. respectively.
Which "trouble-free" is better to choose for a gas boiler:
- To maintain the operation of the heat generator, UPSs of continuous operation (online) with the ability to connect external batteries are best suited. Off line appliances are not suitable.
- If the power consumption does not exceed 0.5 kW, and the shutdown time is 1 hour, a line-interactive unit with a built-in battery is suitable.
- The backup source should give a clean sine wave at the output, this is important for the normal operation of the pump motors. UPSs for household appliances or computers are not suitable for boilers, since they give out the so-called approximated sine wave or quasi-sinusoid.
- In order not to buy a separate stabilizer, choose a device that can smooth out voltage drops in the mains. There are models that equalize the voltage in a wide range - from 120 to 300 volts, however, such UPSs are more expensive than ordinary ones.
- When using a generator, it is necessary to stabilize not only the voltage but also the frequency of the current. Here you need an “uninterruptible” type of online with an inverter, others useless.
- Imported wall-mounted boilers are often sensitive to phase location. If the plug is not inserted into the socket correctly, the unit will go into error. For such a heater, look for a power supply with a through zero.
Clarification of computer UPSs. The approximated sine wave at the output of such devices is well received by the electronics, but the asynchronous pump motors are very hot, humming and quickly fail. That is why an “uninterrupted” with a correct sinusoid is needed.
A new backup power supply should be checked immediately. Connect the device to the gas boiler according to the instructions and try to start the unit in heating mode. If automatic ignition does not work, the unit must be changed to another model.
Uninterruptible and car battery
Using lead-acid batteries from a passenger car paired with a UPS is highly undesirable. But many homeowners do it anyway, the main argument is the lower price of the power source. Why it is impossible to operate an uninterrupted unit with a car battery:
- Batteries for cars are starter, their task is to give a large inrush current, then recharge to maximum. UPS needs traction batteries made using GEL or AGM technology.
- The car battery is afraid of a deep discharge, 2-3 such cycles will happen and its capacity will significantly decrease.
- During charging, an acid battery emits harmful gases and hydrogen into the room. Under certain conditions, it can explode - this is a well-known fact.
- The electrolyte will quickly boil out of the lead-acid battery, you will have to constantly monitor the level and add distilled water, check the density and so on.
- The service life of specialized gel batteries is 6–10 years; a car battery will not “live” even half of the indicated period.
Hence the conclusion: do not operate the UPS for a gas boiler with a battery from a car, unless in extreme cases, as a temporary power source. It is better to purchase specialized traction batteries and not worry.
Conclusion
To successfully choose a UPS for the boiler, you need to identify all the problems associated with the power supply of your country house. Find out in advance the range of voltage drops, fix the duration and frequency of outages. A voltage relay with a display will help solve the problem - an inexpensive device that cuts off electricity during surges in an external network.
Further, it is much easier to calculate the power and choose an “uninterruptible”.If you are using an autonomous power station (generator), find out the parameters of the output voltage that the backup power supply should process.