SIGMA-15 SK and SIGMA SK-35: Technical guide marine power supply unit 13.8 V
Sigma series – marine power supply for river and sea vessels. Both blocks from the technical guide. SIGMA-15 SK and SIGMA SK-35 - provide a stabilized 13.8 V and hold two power supply inputs with automatic switching. SIGMA-15 SK is certified by the Russian River Register (RRR).
13.8 V – Marine radio standard
Most on-board VHF stations, receivers, and navigation devices need 13.8 V, which is the voltage of a fully charged on-board battery. SIGMA units give it stabilized: the equipment does not “float” with the onboard network when engines, winches and other powerful equipment are working.
15 amperes or 35 amperes, consider the load
SIGMA-15 SK produces 13.8 V at a current of up to 15 A - this is enough for the radio, receiver and part of the navigation. SIGMA SK-35 - up to 35 A: the unit takes on powerful VHF transceivers, HF equipment, AIS and navigation devices in one scheme. The entrance to SIGMA SK-35 is wider: 21-36 V direct current from the onboard network or 175-275 V variable from the onshore – switching between sources occurs automatically.
The galvanic interchange
Both blocks are made with galvanic decoupling of the input and output chains. The onboard network of the vessel is noisy: starters, converters and generators sit on it. The interchange does not allow these interferences to go to the communication equipment and does not allow the accident on one side to spread to the other.
For mixed power supply
Both models are convenient on ships with mixed power supply: at the berth power supply comes from the shore network of 220 V, on the go - from the onboard 24 V, and the transition occurs without operator intervention. The equipment continues to work, the watchman notices only the indication of a change of entrance.
Alternatives to the same problem with two inputs NavCom Alfa-2 and Alfa-6 (technical guide NavCom Alpha-2 and Alpha-6If power supply is only required from 220V network, BP-103-20 review Power supply unit and charging for marine radio communications.
Frequent questions about SIGMA
How is Sigma-15 SK different from Sigma SK-35? Current and input: 15 A and 24 V/220 V input at SIGMA-15 SC vs. 35 A and inputs 21–36 V / 175–275 V at SIGMA SK-35. Plus, SIGMA-15 SK is certified RRR.
Why the galvanic junction? The on-board network is noisy - it feeds starters and converters. The interchange cuts off interference from communication equipment and does not allow the accident to spill between the entrance and exit.
Does the block switch between the shore and the board itself? Yes, automatically - when a voltage appears and disappears at one of the inputs.
What SIGMA do you take for radio? Consider the total current of the equipment: the station with navigation usually fits in 15 A, powerful VHF / HF with AIS - take the SK-35.
Power supply unit SIGMA in the repair of the river fleet
If the SIGMA unit is ordered for a vessel on the Volga-Don Canal with receipt in Kalach-on-Don, start with the list of connected equipment and the scheme of the existing power supply. To replace, you need marking of the old source, for a new installation - the design need and the composition of the shield. The name of the series itself does not confirm the suitability of the block for all consumers listed in the article.
When supplying several ships from Volgodonsk, spread the equipment on the sides: what source remains, what changes and what connections are required by the contractor. Documents and a specific configuration are agreed for each position. This statement allows you to compare the quotation on one composition, preserving the difference between the supply of the unit and work in the marine electrical system.
