Post by yachtsmanwilly on Oct 25, 2023 19:01:02 GMT -5
So the owner of the tug I run (sound familiar LOL?) wants to do an update to the DC system. Its a 120 Volt DC boat with a single 3-71 DC generator and a bank of 14 eight volt cells that run all the air and steering on the boat. I get confused since thats 112 VDC. These are locomotive sized batteries, probably 3X the height of standard 8V195s. Maybe 5-700 lbs each. Theres a 30-40 KW Isuzu AC unit for creature comforts.
The batteries are marginal and if the DC generator dies we hafta drop the hook. Theres a small shop sized AC compressor that may hold clutches in but still no steering. Full static charge on the batteries provides about 95 volts after an all day run. That will deplete in a hurry running 100 HPs worth of equipment.
So now if out on a 24 run at a given speed, there is a shaft driven generator in D.C. The owner wants to turn it around and power it with a Perkins or whatever with a Lovejoy coupling. If the DC board isnt manned and the pilot drops the engine speed, the generator can lose its field flash/polarity making the boat go black. That can be a nightmare reflashing in the dark provide none of the fuses etc. are blown.
So the thought of diesel driving the shaft generator direct makes the system redundant. Any thoughts on an affordable non turbo 4 banger to do this with. The owner isnt too worried about being tier compliant. Cooling water is available just below the platform for the Lufkin gearbox, and the stack is a dry unit to the roof.
Thoughts or recommendations?
The batteries are marginal and if the DC generator dies we hafta drop the hook. Theres a small shop sized AC compressor that may hold clutches in but still no steering. Full static charge on the batteries provides about 95 volts after an all day run. That will deplete in a hurry running 100 HPs worth of equipment.
So now if out on a 24 run at a given speed, there is a shaft driven generator in D.C. The owner wants to turn it around and power it with a Perkins or whatever with a Lovejoy coupling. If the DC board isnt manned and the pilot drops the engine speed, the generator can lose its field flash/polarity making the boat go black. That can be a nightmare reflashing in the dark provide none of the fuses etc. are blown.
So the thought of diesel driving the shaft generator direct makes the system redundant. Any thoughts on an affordable non turbo 4 banger to do this with. The owner isnt too worried about being tier compliant. Cooling water is available just below the platform for the Lufkin gearbox, and the stack is a dry unit to the roof.
Thoughts or recommendations?
