Re: [Amel Yacht Owners] M801E HF/SSB Radio power Supply

ngtnewington Newington

Hi Dean,
On Amelia we have the M802 SSB installed by Amel. They chose the DC converter route: there are two Mastervolt 20A converters in parallel. 
These are located under the chart table in the little locker.
There is a breaker to power them up by the chart table porthole.

Is this a good system?

Amel decided it was the way to go. However Mastervolt do not make a 30A version to make your 60A supply. 

Secondly: if the Mastervolt fails and allows 24v direct to the Icom then damage will occur to the radio. An in-line fuse would not blow because only the voltage would be up not the current.

If you use your engine starting battery, and then charge it from the 24v domestic bank with a Mastervolt Magic series 20A it will 
1. be less expensive
2. Be safer for the radio from a power supply basis as even if the Mastervolt failed, and allowed 24v direct to the battery, that would protect the radio. Although there would be potential for damage from applying 24v to 12v battery.

 Why am I worried about Mastervolt DC converter failure? 
Because it happened to me. When I bought the boat. The surveyor powered up the SSB at the breaker. Smoke poured out or the Icom box! I checked everything and one of the converters failed and sent 25v to the radio. Burnt various capacitors etc within the radio. I had it fixed and bought a new DC to DC converter. However I have asked myself whether this is really a good system ever since. I am now paranoid.
So if I am not using the SSB much I disconnect the power supply from the radio then power up and check the voltage is 13.5v before plugging it back in.

So not sure I am helping much. 
Other considerations;
galvanic isolation
Radio interference

Nick Amelia (#019 Aml 54)

On 17 Dec 2018, at 04:39, trifin@... [amelyachtowners] <amelyachtowners@...> wrote:


I am planning a new installation involving an Icom M801E HF Radio (which I already have). The unit needs to be powered from 12V and the specifications call for up to 60A. (This is double the power consumption of the M802 radio used by many North American cruisers. I have a support ticket lodged with Icom to confirm that there is not a mistake in the specs!).

I wonder if there’s anyone in the forum who has installed the 12V version of the M801, who could share their power supply installation details..

Options would appear to be:

1: High power (60A) DC-DC converter(s) running from the 24V bank. (Isolated type is preferred, which means two units in parallel are required, although I’m not convinced this is absolutely necessary).

2: Tap 12V power from upper or lower half of house bank, connect house bank mid-points and install a battery balancer. A bit ugly really.

3: Install isolated low power (10-20A) DC-DC Converter between house bank and engine battery and power SSB from engine battery. DC-DC Converter replenishes battery in slow time and alternators provide bulk and eq charge. I like this option from a low-noise perspective. Nothing else is connected to this battery, and if conducted emissions are a problem from the DCDC converter, just switch it off. And in the event of an unforeseen/unlikely complete discharge event, there are another 12 batteries available to start the motor/genset.

4: Others?

Many thanks
SY Stella

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