This lesson summarizes what Furuno's installation documents ask of the boat. It is background for an owner; the install itself is for a qualified technician.
At a glance
- Mount 1/3 to 1/2 of the boat's length from the bow, on or near the keel
- Standard 8-inch tube: 216 mm outside, 190 mm inside
- Ground every unit with a copper strap
- Record noise at anchor and at speed on the sea trial
About 8 minutes. Part of Own it in the CSH-8L MK2 course.
Where the hull unit goes
Between one third and one half of the boat's length from the bow, on the keel if possible, otherwise with the tank center within a meter of it. Keep it at least 2.5 m from other sounder transducers, with no obstruction ahead that would aerate the water, and 800 mm of service clearance. Keep the compartment above freezing and the transducer cable away from oil.
The tank
The standard Furuno 8-inch tube has a 216 mm outside diameter and a 190 mm inside diameter, and is supplied at 1,000 mm. Furuno shows cutting it to 750 mm for the 600 mm stroke unit or 550 mm for the 400 mm unit so that the dome clears the keel, and Furuno USA's guide gives longer minimums, 800 and 600 mm. Weld beads must not protrude inside, and the gap between the tank and the guide is about 1 mm. A fairing is available for fiberglass boats.
Choosing the hull unit
The hull unit is chosen by tank length. On a retrofit from the CH series the tank need not change. Shaft collars are not required but are recommended to stop kelp and rope from pulling into the tube. The dome comes with about 6.6 m of cable, of which about 5 m remains after the shaft; the CSH1700 kit adds 6.6 m.
Power and grounding
The processor takes 100, 115, 200, 220 or 240 VAC, and a DC-AC inverter allows 24 VDC ships. The transceiver is jumper-set for the supply. Ground all units to the ship with a copper strap; protective earth on the transceiver and inverter is mandatory. Do not run power next to signal cable. Compass safe distances are 0.4 m for the processor, 0.3 m for the control unit and 1.4 m for the inverter.
Setup and sea trial
After installation the installer sets HEADING ADJ, AUTO RETRACT, the log and gyro items, the ports and NAV DATA. On the sea trial, record the noise level at anchor and at speed, and photograph the best settings. You will want those numbers the first time something changes.
Check yourself
Three questions
Sources
- CSH8LMK2 Installation Manual: Chapters 1 to 3 and appendices
- CSH8LMK2 Installation Guide: Installation guide
- CSH5LMK2 CSH8LMK2 Operator's Manual: Specifications
This lesson summarizes Furuno's public documents in our own words. Limits and settings differ by model and software version, so your own manual and your installer have the last word. OmniCSH is an independent project, not a Furuno program.