Modern heating systems, including gas-fired ones, according to the instructions for use, operate in a continuous mode and need protection against accidents on power lines. The dependence on power supply is even more true for power units equipped with instrumentation and a pump. Frequent interruptions in the supply of electricity disrupt the normal operation of the device, sometimes causing it to break down. Since the power failure usually occurs for a short time (from 5 minutes to a day), a typical UPS for the boiler is used to protect the power line.
When you need a UPS for the boiler
The issue under consideration is of particular importance in rural areas, where unstable energy supply has recently become almost the norm. In summer, in hot weather, it does not bother the owners too much, but in winter, during the heating season, it will be necessary to take drastic measures to protect the equipment and maintain its performance.
To a large extent, the problem with power instability concerns country houses and cottages, where purchasing an uninterruptible power supply for a heating boiler is the only right decision.
An uninterruptible power supply unit for a heating boiler is in demand in the following typical situations:
- heating equipment is used in areas with unstable power supply;
- the operation of the heating system is caused by the need to maintain a comfortable air temperature in the winter season;
- at urban substations, there are constant outages due to uneven distribution of loads across the serviced facilities.
The purchase of a UPS for a gas boiler will resolve the issue of unstable power.
Principle of operation
To smooth out fluctuations in the voltage in the network or protect against short-term loss, the principle of double conversion is used, which consists in the following:
- The corrected AC voltage is fed to the mains filter, which smooths out sharp fluctuations by limiting the RF harmonics.
- It goes to a diode bridge, which converts the alternating component into a constant one.
- If necessary, part of the rectified current is spent on the charging circuit of the standby battery used in a situation when the voltage disappears for a long time.
- Its main part goes to the inverter, in which the reverse conversion of the constant component into the variable is carried out.
- The stabilized voltage obtained in this way is suitable for powering a solid fuel or gas boiler.
The advantage of the double conversion UPS circuit is the absence of a bulky autotransformer. A device operating on this principle guarantees continuous, instantaneous voltage correction. If necessary, it can work using the energy stored in the batteries.
UPS requirements
To find out which uninterrupted unit is suitable for a gas boiler, you need to decide in advance on the requirements that apply to the device. Familiarity with the main indicators of the UPS, which characterize the efficiency of its operation, will help. Some of them:
- Active and total (taking into account the reactive component) power, defined as the product of the supply voltage and the current in the load.
- The harmonic distortion factor, indicating the quality of the output voltage - the deviation of the sinusoid from the ideal form.
- The presence of an external battery, which allows not to interrupt the operation of the boiler in the absence of the mains power supply for several hours.
- The duration of the offline operation.
- The limits of permissible fluctuations of the input voltage in Volts.
The duration of work from the battery depends to a greater extent on its capacity.
When, according to the operating conditions of the boiler equipment, long interruptions in the power supply are expected, it should be possible to connect additional batteries. It is also desirable that the purchased device has the function of automatically monitoring the state of the power supply and restoring the normal power mode.
Especially "advanced" models are encouraged to have the option to diagnose the battery status. However, such samples rarely top the popularity ratings of protective uninterruptible power supplies, since they are too expensive.
Which UPS to choose for a gas boiler
- functional capabilities of the device (double conversion, battery, etc.), as well as ease of installation;
- the reliability of the manufacturer of the electronic conversion device;
- guarantees for the period of trouble-free operation of uninterruptible power supplies for gas boilers - the indicator should not be less than 5-7 years;
- noise level during operation;
- the selected model has a quality certificate.
Taking into account the above points, the user can go to the store and choose the model of the inverter converter that is suitable specifically for his boiler.
Back-up time calculation
Taking into account these two indicators, the formula for calculating the required time interval takes the following form:
T = E x U / P x KPD x KDE (in hours), where
- E - the total capacity of the connected batteries,
- U - operating voltage of the battery,
- P - active power in the load.
The coefficient for the inverter KPD is close to 0.8, and the same figure for the battery (KDE) is about 0.9. They are not fixed values and depend on a number of operational factors: the amount of energy consumption, as well as on the temperature and humidity of the air.
As an example, several options for calculating the autonomous operation of the "Shtil" UPS are presented. With an initial voltage of 12 Volts and a total capacity of 60 Ampere-hours, the UPS is used for a wall-mounted heating boiler with a declared power of 150 W. In this situation, the time of its independent work is obtained: T = 60 x 12/150 x 0.8 x 0.9 = 3.5 hours.
When considering an option with a battery capacity equal to 150 Ampere-hours, this indicator for a boiler with the same energy costs will be: T = 150 x 12/150 x 0.8 x 0.9 = 8.6 hours.
In the presence of two batteries with the same capacity, the time of its operation in the absence of voltage in the network will be equal to: T = 2 x 150 x 12/150 x 0.8 x 0.9 = 17.2 hours.
The given calculation methodology is suitable for any range of UPSs, including the common models Baxi, Bosch, Vaillant and Buderus.
With an increase in the number of storage batteries, the required period of time increases. Its extension is facilitated by the choice of the optimal mode of operation of the boiler from independent power sources.
Installation features
Anyone who plans to install a UPS for a gas boiler with their own hands will first need to familiarize themselves with the rules for its installation and connection. When choosing a place for installing this unit, it is necessary to take into account that it is recommended to place the UPS and the battery for the gas boiler in the areas of the service room that are well protected from humid vapors. For these purposes, a sealed cabinet, located as close as possible to the ventilation shaft, is optimal. This position will protect the backup equipment from excess moisture in the form of condensate and will maintain the required cooling mode.
In addition to choosing a place, the desired microclimate in the room is ensured by maintaining the air temperature within 18-25 degrees. In this case, the capacity of the batteries is maintained at the maximum level, so that the UPS can operate for a long time.
To all the listed features, the following must be added:
- The dust level of the room with the UPS and the boiler must be kept to a minimum.
- The source case is subject to mandatory grounding using a full-fledged charger (protective circuit). In his absence, it is allowed to organize grounding through the same bus to which the heating unit itself is connected. To do this, you will have to stretch a separate copper conductor from the UPS ground terminal to the corresponding contact of the boiler.
- in the boiler room, a supply ventilation system is required, which ensures effective air purification from gas emissions (they are formed during the electrolysis reaction in the battery).
Before installing the equipment you just purchased, just before installing it, you should take a short pause so that the temperature of the case equals the room temperature. Such exposure will avoid the formation of condensation on the internal surfaces of the UPS and the ingress of moisture into the working units. When placing remote batteries and the source itself directly on the floor, it is advisable to use a special substrate in the form of a rubber mat. When connecting additional consumers to the stabilization module, it is necessary to calculate their total power in such a way that the obtained indicator does not go beyond the permissible limits. As a rule, it is chosen so as not to exceed 50-60% of the rated power.
When installing and operating a set of equipment, it is strictly prohibited to:
- connect the source in parallel with the mains supply line: the effect of the UPS operation is possible when it is connected between the mains and the consumer;
- cover the body of the device with foreign things and objects that restrict the access of fresh air;
- periodically overload the device in excess of the permissible power limit indicated in the accompanying documentation (passport).
Carefully observe the polarity of the battery connection to the UPS. Failure to do so could result in equipment damage.
To extend the service life of the backup power system, it is not allowed to combine more batteries with a loop than specified in the technical documentation.
