ALFA-2 or ALFA-6 for two devices: calculate the total current
NavCom Alfa-2 is a catalogue image. The second block in question, the Alfa-6, is shown below with reference to its own card.
Request a quoteOne radio and another device may individually meet the power supply unit limit, and together exceed it. Therefore, the choice between the NavCom Alfa-2 and Alfa-6 begins with a list of simultaneously operating loads. The number of output connections does not increase the permissible total current of the source.
Example: Each load is suitable, the amount is not
Suppose that the first conditional consumer requires 6 A in active mode, the second - 5 A. The total load is 11 A. This is a study quantity, not a passport consumption of the specific radio of our catalog. Comparing separately 6A to the block limit, and then separately 5A is a mistake: the source must provide both consumers in the same mode.
According to the manufacturer, the Alfa-2 has an output of 13.5 V with a maximum current of 10 A at 100% cycle. For the described mode 11 A is already above this indicator. Calculation does not become permissible because each device has its own wire or switch. If the loads never really work at the same time, this should follow from the accepted system mode, not the seller’s assumption.
Why 12A doesn't make Alfa-6 a universal replacement
For the Alfa-6, the manufacturer specifies an output of 13.5 V and a maximum output current of 12 A at 100% cycle. The arithmetic of 11 A is less than 12 A, but this is not enough for the final choice. Check short-term peaks, equipment start-up, the permissible voltage of each consumer and the operating conditions of the unit. The arbitrary same “percentage reserve” does not replace documentation requirements.
The primary power supply is also different. Alfa-2 is designed for network inputs 220 V AC and 24 V DC, Alfa-6 - for input 24 V DC. Therefore, higher output current Alfa-6 does not automatically retain network input and functions of the previous node. If the equipment is to continue to operate when the onshore power supply is disconnected, the entire operating circuit and reserve are first considered.
Check out several working combinations
For the station it is useful to write the current of reception and transmission, for the second device - duty and active modes. Then choose combinations that can actually occur together. In the table below, the first line shows calm mode, the second - simultaneous operation. Checking only the average consumption per shift is able to miss the most demanding mode.
Currents at the input and output are different characteristics. The maximum input current from the Alfa-6 table cannot be used as the allowed load of its output. You also need to check the distribution of circuits, protection and voltage drop in the line. This is the task of the agreed installation scheme; the sequence given is not an installation instruction.
Ordering one block or sharing power supply?
One suitable source reduces the number of individual devices. Separate sources may be required due to different voltages, backup functions, or system requirements. By itself, adding a second unit does not make power supply independent: both may have a common primary input. Purchase is discussed taking into account the role of each consumer and the admissibility of a common point of failure.
Both models are presented in our cards below. In the request, specify the number of blocks, the required primary network and the load table by mode. Cables, protection and installation are not declared included in the price of the block without an agreed quotation. Current availability and configuration are confirmed before ordering.
- Primary network: AC/DC or DC only
- Table of simultaneous regimes
- Selection of the block and coordination of the scheme
A simplified scheme for order approval. The spinning and working connections are determined by the documentation of specific devices.
| Conditional combination | Total current and output |
|---|---|
| First 1 A + second 2 A | 3A; this is not a maximum mode test |
| First 6 A + second 5 A | 11 A; above output 10 A for Alfa-2 |
| Same 11 A and Alfa-6 12 A | The arithmetic limit is met; peaks, voltages and conditions still require verification. |
Questions before ordering
Can two 6A devices be powered from a 10A source?
At simultaneous load 6 + 6 = 12 A, which is higher than 10 A. A separate comparison of each device with the source limit is incorrect.
Alfa-6 automatically replaces Alfa-2 because it has 12 A’s.
Nope. The primary inputs and functions of the node differ. The Alfa-2 has 220 V AC and 24 V DC, while the Alfa-6 has 24 V DC primary input.
The 6A and 5A shown are the costs of the radio we sell?
Nope. This is a conditional calculation to explain the amount. For order take passport data of real consumers in all required modes.
Both models in our catalog
Two alternatives to select by primary network and design load. They are not declared to be a common set of two blocks; the quantity and composition are agreed in the quotation.
Delivery to Russia and Kazakhstan. Indicate the city - agree on the cost and delivery time of the selected set. Current availability, condition, documents and exact completeness are confirmed before ordering.
Request a quotePower supply parameters: Manufacturer's card NavCom Alfa-2 / Alfa-6, NavCom Alfa-6. Selected configuration and scope of supply are checked separately.