s/v TWIG

Saga 43 - Hull #39

Electronics

Over current protection

All electronic equipment serviced by the yacht’s 12 and 24 volt electric circuit should be separately protected by a fuse or circuit breaker of appropriate size. If a large number of electronics are to be added, a branch panel of breakers may be required. Make sure that the polarity for electronic accessories is correct, and that they are installed according to the manufacturer’s recommendation.

GGA

Through Hull Fittings

If other than standard through hull fittings are required and are to be added after the yacht is built, consult a service department to determine the correct positioning of the through hull fitting. Directions concerning the components and installation of the through hull fittings should be supplied with the unit. Remember that the hull contains core material. Refer to Sec. 8-3 for areas that were left intentionally without.

Masthead Fittings

Masthead fittings should be installed carefully, following manufacturers recommendations. Your SAGA mast contains an internal wiring conduit, all cables must be fed through the conduit to prevent chafing and tangling with the internal halyards and other cordage. Cables leading from the masthead fitting exit the mast above the cabin sole and enter the bulkhead into the forward stateroom under the berth as provided for mast light wiring. A connector should be installed at this point which facilitates easy disconnecting whenever the mast is unstepped. Keep all connectors, junctions and wiring as high in the yacht as possible to prevent them from coming in contact with bilge water.

Magnetic Compasses

Magnetic compasses are adversely affected by electromagnetic waves generated by electrical equipment as well as by large metallic objects. The pedestal steering compass supplied with your boat must be checked and re-compensated after the final installation of all aftermarket electronic gear.

All compasses have some error, called deviation, which will vary at different headings. We recommend that the compensation procedure (called “swinging the ship”) be performed only by a competent professional who can supply you with a deviation table for any remaining compass error that cannot be removed by the internal compensation magnets. Furthermore deviation should be determined with engine running and not running; and with major electronics both on and off to check for their effect on deviation.

The electronic compass is similarly affected by metallic objects and nearby electronics, just like the steering compass. The autopilot manual gives instructions on swinging the ship and built-in compensation techniques. The electronic compass is located under the forward berth against the main bulkhead.

Be very careful never to store tools, canned goods, or other heavy metal objects within 3 feet of the compasses on board. Stereo speakers and portable radios are a particularly strong magnetic source. Even a beer or soda can stored in the pedestal mounted drink holder may affect the steering compass. Be vigilant at all times about the storage and the installation of additional electronic gear.

SEE ANNAPOLIS BOOK OF SEAMANSHIP. John Rousmaniere, Chapter 7 for a discussion of this highly important topic.

edit