EV-1 location

[DFMott]

I am looking for some help in deciding where to locate my EV-1 sensor. I have a Scout Abaco 262 and I am having difficulty identifying a location that will work. First - there is no place that is three feet away from all potential sources of interference. I am not an expert so I don’t know the trade-offs of being further away from center or the waterline.

Here are the choices I am debating -

Inside the head behind a panel about 12” off the center of the boat and close to the waterline. The issue here is that it is 12” away from the toilet macerator which contains an electrical motor. The other water pumps are about 20” away and below it . The big advantage here is that it is totally hidden and convenient to wire as it will be on the same plane as the controller and ACU.

In the center compartment against the back wall. The advantage with this location is that it is very close to the middle of the boat and centered. However mounted right in front of it on the other side of the fiberglass is the ProNautic 12.50 battery charge which may create issues even though it won’t be running when the boat is underway. All other water pumps will be 20” away.

The third option is in the storage compartment under the bunk in the cabin. It is near the middle of the boat (slightly fore) and can be centered near the waterline. The big question here is that it would share the space with the AC unit. That being said, the compressor motor is 30” away and the control box for the AC is 16” to the left.

The last place under consideration is on the console opposite the compass. The advantage is everything that could cause interference is at least 24” away (I am assuming the compass would not be a source of interference). The big disadvantage is there is no clean way to get a cable to it without running an exposed cable on the ceiling of the cabin and it is far from the waterline, 12” off center.

This is my first time installing an Autopilot so any guidance is much appreciated.

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Don,

Of less importance is the location of the EV-1 Sensor Core with respect to the vessel's centerline and mid-ship. However, the first three locations which you have identified would be deemed unsatisfactory due to the presence of devices creating large magnetic fields being located within 3' of the EV-1 Sensor Core. Should the last location which you have identified be unsatisfactory for mounting considerations or cause the EV-1 Sensor to be located within 3' of devices constructed of ferrous material or creating large magnetic field, then an alternate location will need to be researched. You may want to look at potential mounting locations below the boat's deck.

[DFMott]

So being close to the waterline and centered midship is not important?

3 feet away from anything metal is difficult on my boat. What about things like the Radio speakers? Metal Gas Tank? Metal handrails? Chair Pedestal? Battery? There is something within 3 feet of every possible location on my boat and I am just not sure what has an effect and what doesn't. Wish there was a database containing mounting locations by boat manufacturer and model.

I could mount it on the console right behind the windshield but there is a metal support (stainless) that would be behind it and a metal frame around the split windshield that will be right in front of it - not sure but probably aluminum. A 6.5" JBL round speaker would be 24" below it in the cabin. Compass would be next to it about 12" away.

I have identified another location which may be the best choice so far. It's under the galley and about 22" left of center and 4' forward but very near the waterline. It is 3 feet or greater from any pump or motor including the AC unit. The closest power cable is 18" behind it at it's closest point. There is a Stainless Steel Sink that is above and behind it and 16" at its closest diagonal distance. I'm not sure if that would cause interference as Stainless Still is not magnetic (or at least a magnet doesn't stick to it). My concerns are it being 22" left and 4' forward of center and whether or not the 2 things that might interfere are a concern.

[Chuck - Raymarine - Moderator]

Don,

Please click here to view a FAQ addressing the importance of maintaining separation of the autopilot's magnetic north seeking component from objects producing magnetic fields. As grades of stainless steel will vary in their ferrous material content, it is recommended that a magnet be used to test for ferrous or magnetic material content of suspect items. Should the magnet stick to or be repelled by the object being tested, then the object would be deemed to feature ferrous or magnetic material. Your concerns the location being 22" left and 4' forward of center are far less important to the performance of the autopilot than would be the impact of installing the EV-1 Sensor Core within close proximity to an object producing a strong magnetic field. As indicated within the FAQ, should a satisfactory location not be found below deck, then you may want to consider mounting the EV-1 Sensor Core on the hard top.

[jegnew]

I have an Amazon 44 (steel) pilothouse sloop and am trying to find a suitable location for a new heading sensor (EV-1). How strong a magnetic field is too strong? I'm using Gemeco's magnetometer app.

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum jegnew,

We generally recommend that deviation not exceed 9 degrees. With steel hulls, it may be necessary to install the EV-1 CCU above decks.

[jegnew]

I assume the "9 degrees" refers to a hand held magnetic compass. You have previously mentioned using a magnetometer. What field strength is too much?

[Chuck - Raymarine - Moderator]

jegnew,

The specified maximum deviation is that which would be sensed by the EV-1 CCU.
Raymarine has not identified a maximum field strength. The suggested tool is typically used to sense relative field strength. Your suggestion to utilize a handheld compass may be useful in obtaining an approximation of the magnitude (in degrees) of the deviation for the mounting location in question. For installations such as this, it would typically be recommended that the EV-1 CCU be mounted in a temporary fashion to permit it to be relocated should the selected location result in excessively high sensed magnetic deviation.

[jegnew]

I've been ruminating and considering options. So I did not suggest using a magnetic compass. That has been suggested elsewhere in this forum. But anyway, I'm considering locating the EV-1 on a pole above my Quantum Radar with is mounted on a stern arch. Is 16 ft. above the waterline too high?

[Chuck - Raymarine - Moderator]

jegnew,

My concern with your suggested location is that the radar transducer feature electric motors which may adversely effect the performance of the sensor. Have you considered installing the EV-1 on the leading edge of the mast?