Connecting Raymarine E7 RF Drain/Ground on Jeanneau SO32

[Drumm]

Hi, I'm about to install a Raymarine E7 MFD to the cockpit of my SO32i. Does anyone know whether the Jeanneau SO32 has a dedicated RF ground and if so where is it? The Raymarine has a separate RF drain wire in addition to the 12V red +ve and black -ve wires. The manual says that the RF drain wire should be connected to the boat's dedicated ground if it has one, otherwise to the battery -ve terminal. Research elsewhere has also suggested it should be connected to the engine block.

Any help greatly appreciated.

 

[pvb]

The manual says that the RF drain wire should be connected to the boat's dedicated ground if it has one, otherwise to the battery -ve terminal. Research elsewhere has also suggested it should be connected to the engine block.

I can't imagine the RF ground is crucial on a plotter, so I'd just follow the instruction to connect it to battery negative.

 

[PaulRainbow]

I can't imagine the RF ground is crucial on a plotter, so I'd just follow the instruction to connect it to battery negative.

Definitely +1 (in the absence of a dedicated ground, which i highly doubt exists on the Jeanneau.)

 

[Bru]

I can't imagine the RF ground is crucial on a plotter, so I'd just follow the instruction to connect it to battery negative.

It's not an RF ground, it's an RF drain (usually a chassis ground at least) intended to carry away any RF interference to (ideally) an infinite ground e.g. a hull grounding plate or a bonding system

Edit: Half an answer, here's the other half! ...

The advice / guidance to connect the drain to the battery negative is really intended for outboard engined boats. The manual and the stock answer from Raymarine tends to assume, because its the American way, that larger boats will have a full bonding system in which case the drain should be connected to the bonding point.

From a Raymarine tech ... "Should the vessel be equipped with a bonding plate and bonding cable, then the drain leads should be joined and connected to the bonding cable. Should the vessel not be equipped with a bonding cable and be equipped with an inboard engine, then the drain leads from Raymarine products should be joined and connected to the engine block. Should the vessel not be equipped with a bonding cable or inboard engine, then the drain leads from Raymarine products should be joined and connected to the negative post of the battery."

The object of the exercise is to connect the drain as directly as possible to the biggest available RF sink. The ocean is an infinite sink! Failing that, the engine block is a pretty big one. A battery is better than nothing.

 

[Ric]

Just connect it to the black wire. The SO definitely does not have an RF grounding plate - it is not the sort of boat which you would fit SSB radio to, and there is no way that a budget manufacturer like Jeanneau is going to waste money on something that nobody would ever use. The RF ground is not, in any case, to protect the E7 from interference, it is to prevent the E7 from interfering with an SSB radio. If you haven't got an SSB don't worry about it.

 

[Bru]

Just connect it to the black wire. The SO definitely does not have an RF grounding plate - it is not the sort of boat which you would fit SSB radio to, and there is no way that a budget manufacturer like Jeanneau is going to waste money on something that nobody would ever use. The RF ground is not, in any case, to protect the E7 from interference, it is to prevent the E7 from interfering with an SSB radio. If you haven't got an SSB don't worry about it.

You can do that and 99 times out of a 100 it will work fine with no problems. But it's not just a MF/HF radio that can be adversely affected by RF interference. The VHF set can be too, as can WiFi (and the E7 has WiFi built in of course), mobile phones, bluetooth equipment, radar etc etc. Modern boats usually have a whole bunch of devices that use radio of one form or another, Plus, RF interference can adversely affect non-radio devices too.

I'm not going to say "don't do it", the reality is most installations that is exactly what is done, ,but if you do go quick and dirty on the RF drain just make a mental note that if you get funny things happening on your electronics at a later date, which might not even manifest themselves as obvious interference, it might be 'cos you took a shortcut

 

[Drumm]

Thanks for all the replies and advice. I made a closer inspection of my boat and found that where a large anode has been fited to the hull towards the stern, the protruding stainless steel studs inside have been used to create a common ground plate of sorts with a number of earth/ground cables connected. I'll follow Bru's professional advice and connect the RF drain to this point.