Seakeeper 7000A GYRO, Руководство по установке

Страница: 9 / 58

INSTALLATION
MANUAL
Product: Document #: Rev: Page:
MODEL 7000A GYRO 90051 3 7 of 10
Section 1: MECHANICAL INSTALLATION
Safety Enclosure
There is a large torque about the gimbal axis when the gyro is precessing. Therefore, the gyro
must be housed in an enclosure or a compartment or installed in a cage so personnel or gear
cannot come into contact with the gyro while it is precessing.
The gyro should be treated with the same respect one gives a high speed rotating propeller
shaft or engine shaft. The gyro must be installed so contact is not possible while the flywheel
is spinning.
Noise/Soundproofing/Ventilation
Gyro noise has been measured under steady state conditions (no wave load) in Seakeeper's lab and in
our 43 ft Viking test boat. The steady state noise is typically in the range of 70-75 dB unweighted. As the
frequencies emitting the highest sound pressures are low (like other marine machinery), it is
recommended that the gyro be installed in a cage in a machinery space that is already treated with
soundproofing.
If the gyro stabilizer has to be located outside a machinery space, it should be installed in a sound
damping enclosure to prevent low frequency noise (approximately 160 Hz) from entering the living
spaces. In this case, the enclosure can be open at the bottom between the hull stringers. A small
exhaust fan should be installed in the top of the enclosure to pull ambient air thru the enclosure so the
air in the enclosure does not heat up. This will ensure that the owner does not get nuisance shutdowns
due to the Motor Drive and Bearing temperature alarms in some operating conditions (high ambient air
temperature, high sea water temperature, high sea state, etc).
The fan should deliver 35 cu ft/min (60 cu m/hr) which should exchange the air in the enclosure about
once per minute. Small, mass produced, axial and centrifugal cooling fans are available with either AC or
DC input power, ball bearings, extended temperature range, low noise ratings, long MTBF, marinized,
etc. Locate the inlet at the bottom of the enclosure and mount the fan at the top as an exhaust fan. A
centrifugal fan may be best to minimize outlet area. The fan power requirements would typically be in
the range of 20 watts. When using a DC fan, wire it to the same breaker that provides power to the
Gyro Control Junction Box so the fan turns on and off at the same time as the controller.