wingless' Marine Air System

Automotive Onboard Air Systems
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My 2000 380 Searay Sundancer is about to get a custom air compressor now, then add a horn and maybe an air whistle system later.

The first step was selection of a compressor. I have a Oasis XD3000-12 compressor. This has been customized to add features like forced air cylinder / head cooling, like is present on the XD4000-12 compressor, only mine has much more airflow and mine has ductwork to suck in fresh, exterior air.

The compressor is located in an inaccessible / unusable area of the hull, between the inner and outer hull. This volume is outside the ignition-protected environment, where it is prohibited / unwise to install anything that makes a spark, like this compressor, that could ignite gasoline vapors, even though those vapors should not exist. This is an ABYC (boat) requirement. When I inspect the compressor, like for checking the oil level, I need to unscrew and slide-out the ice maker. Then I have excellent access.

The compressor location has access to exterior air, but not enough to provide acceptable cooling. My system has one of these 4" 220CFM SHURflo yellowTAIL In-Line Blowers w/ ducting to the exterior, then to a custom shroud dumping onto the compressor cylinders / head.

This location is very handy. It is directly above my battery bank. I am using one of these 200A Blue Seas Systems 187-Series Circuit Breakers to provide both the circuit protection and the power feed on / off function. The compressor is wired to power the fan whenever the compressor is running. I will monitor the head temperature to determine if it would be better to reconfigure the fan power to have the fan instead thermostatically controlled. I also have a dash-panel enable / disable switch for the compressor.

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My system maintains the tank at 200 p.s.i. using a Oasis pressure switch, then regulate the output w/ a high-CFM adjustable regulator. My system uses the largest plumbing and fittings that will fit, necking down only where required for the devices utilized. The regulator will be positioned to be accessible w/o dismantling the boat.

The pump is a TCCI Manufacturing LLC, model EA210L, two-cylinder 10 cubic inch compressor, once produced by Borg-Warner. One intended usage for this compressor is for refrigeration. This appears to be an excellent well-made compressor, that is designed for durability.

The TCCI Service Manualdoes not mention oil changes. At this point I will inspect / add oil, but not perform oil changes.

The Oasis XD-3000 compressor uses a Trombetta 684-1251-012-02 continuous duty contactor to switch the high motor current on and off.

Mine has the Advanced Motors & Drives 140-01-4013 12V/24V 4.8KW DC motor.

This is a heavy-duty motor w/ Class H 180°C insulation.

These are all very good components, for a well-built unit.

3

The compressor location has access to exterior air, but not enough to provide acceptable cooling. My plan is to use one of these 4" 220CFM SHURflo yellowTAIL In-Line Blowers w/ ducting to the exterior, then to a custom shroud dumping onto the compressor cylinders / head.

Here is the design for the custom shroud and the location for the fresh air 4" duct input for the head / cylinder cooling for my Oasis XD3000 compressor.

This permits me to relocate the on/off switch to the shroud. The low-voltage indicator lamp is relocated to my dash rocker switch, having one indicator lamp for power, one for low voltage.

CAD Design

Welded Shroud and Inlet Locator

Exterior Air Inlet

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This is the Nason CD-1B4-150J/WLVT187 100 to 250 p.s.i. adjustable pressure switch. According to the linked data sheet, this is a 100 - 400 p.s.i. adjustable switch w/ a ¼" NPT male connection, normally closed contacts, adjustable rising setpoint, 18" wire leads, Viton 514 AD diaphragm, w/ a slotted head, instead of Allen head, adjustment lock screw.

The NEMA rating on this pressure switch is NEMA Type 4 and NEMA Type 13, w/ some protection from water and dust.
The specification sheet lists a 10-20% setpoint to restart point differential hysteresis.

This is the check valve. It is a Control Devices CA-12 Load Genie Unloading Check Valve. It is a 3/8" NPT valve, rated for 3 to 12 CFM flow.

The internal moving mechanism could be hurt by excessive torque. The instructions specify 10 ft-lbs of tightening torque, maximum.

The installation uses a combination of flexible hoses and rigid pipe for the air distribution.

The compressor is connected to a 3/8" diameter by 2’ long Viair Stainless Steel Braided Leader Hose. This will provide vibration isolation from the compressor.

The system uses rigid 1" diameter Type L copper tubing and 95-5 Tin - Antimony solder for the primary distribution. This is around the compressor and the engine room. According to this table these materials provide sufficient rating to operate at the planned 200 p.s.i. My plan is to run the tank and plumbing at 200 p.s.i. up to the high-CFM regulator that feeds the valve then the horn.

My system is using this 15 gallon, 200 p.s.i. working pressure tank. I have mounted this upside down, bolted to the ceiling of the engine room.

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The tank was sanded down for a fresh paint job.

The threads for the port openings were all chased w/ the appropriate-size pipe thread tap, to clean out any prior crud.

The nipples were all selected to be the extra-thick wall Schedule 160 seamless black steel parts, to tolerate the 200 p.s.i operating pressure.

The tank has one ¼" fitting, that was used for a drain, but I have mounted this upside down, so I have used the high-pressure forged black steel square head plug for this and for all other unused fittings.

There are three ½" NPT fittings across the top, now bottom, two are plugged, one is being used for a drain.

The side ports are 3/4" NPT. The air entry has a short nipple, then a 3/4" to 1" coupling, another short nipple, then a dissimilar metal union, so all the rest of the plumbing can be 1" Type L copper.

My hope / plan is to have the air passages as large as possible throughout the system, all rated for 200 p.s.i. working pressure.

My preference is to use pipe dope, instead of tape. On this project, I assembled the fittings, cleaned off the dope, then painted.

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This system has been mounted on a boat w/ gasoline engines. As such, the compressor and all other electrical components need to either be ignition-protected (won’t make a spark) or must not be mounted in the engine room (which extends to a defined ignition-protected volume), both to be compliant w/ the ABYC standards and to follow common sense and not create the possibility to blow up.

On my boat there is a volume alongside and aft of the ice maker, on the port side of the boat that is outside the ignition-protected volume. The compressor is mounted in this volume. It has access to forced fresh air, via a duct and blower, dumping air onto the cylinder head and providing air to the compressor intake. Excess air exits through existing openings.

The initial testing shows GREAT results. There is a HUGE volume of air dumping across the head, using the blower and my custom shroud.
It is close to an ideal location. It is a short electrical run to the battery banks. (It will be wired through a 200A circuit breaker to three 125Ah AGM batteries and I can easily connect two more, if required.) It has plenty of fresh air. My preference is to bolt components in-place, but I cannot do that w/ the compressor, so I am using the 3/4" plywood that will be lag-screwed onto the deck. (One of the 140 gallon fuel tanks is below that deck, so I cannot access the other side to position a nut or bolt.) The oil level will be visible only after sliding-out the ice maker. This is a dry location, not exposed to any water.

The new plywood mounting plate is epoxy-coated, along w/ the rest of that volume, on top of existing resin and gel coat, for additional protection.

Part of the installation is to remote mount the on/off switch, on/off indicator and the low-battery indicator onto the dash, w/ all the other switches. I was able to locate a SPST switch w/ two indicators that matches the existing switches and will fit into an existing empty position.

This custom installation requires that I design and create a circuit to take the existing integrated LED indicator / circuit and make it instead drive the new incandescent indicator in my new dash switch. I designed, built and tested that new circuit. It works great. The second indicator comes on, as-expected, when the battery voltage drops low, when the compressor shuts-down due to low voltage.

New Switch On

New Switch Low Battery

Compressor Mounting Location

Compressor Dry Fit

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Impressive work. Love the boat.

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Excellent job with the install and comments! :smiley:

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Wow! Great detail & pics!:smiley:

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Here is some more information on my custom air system.

This 200 PSI 15 gallon Manchester Tank is mounted upside down in the engine room, bolted to the engine room ceiling / floor of the transom locker storage compartment.

A scissors jack was used to push the tank up against the ceiling to bolt it tightly in-place.

The system is plumbed w/ 1" pipe / tubing throughout. The 1" Type L copper w/ 50/50 Tin/Lead solder is used from the tank through the regulator, to the air chuck and to the 1" ID 300 PSI Buna-N flexible hose, going through the arch to the horns and whistle.

As much MAP torch soldering as possible was done off the boat. The fiberglass and gasoline are WAAY to flammable.

This is the manifold leading from the tank to the regulator and the fill hose / check valve.

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This shows the manifold from the tank exiting the engine room above my six Group 31 125Ah Lifeline AGM batteries. My boat has three battery banks, the starboard bank w/ three batteries for the house, the port w/ two batteries for the helm electronics and the generator has one battery. I also have a rotary switch to short the port and starboard banks into one five battery bank.

This also shows the Blue Sea Systems ANL Fuse Block holding the 200A fuse leading to the Oasis compressor. The ABYC marine standards require this to be placed close to the battery.

This plumbing is visible when opening the engine room compartment.

This is the continuation of the manifold, outside the engine room. This plumbing is hidden by screwed-in-place storage compartment bins. This shows the check valve and hose from the compressor and the plumbing leading to the regulator and pressure switch.

This is the manifold from the regulator to the pressure switch.

Here is the regulator, pressure switch, Blue Sea Systems on/off 200A circuit breaker, air chuck and manifold leading to the horns and whistle.

This compartment is accessible when opening a door. This compartment is used to hold my fire extinguishers and safety flares.

Here is the manifold leading from the regulator, to the air chuck and to the horns and whistle. This manifold is hidden in the volume behind my ice maker and is accessible by removing the screwed-in-place ice maker.

12

Solder job looks nice. Wonder what PSI it can hold versus brazing.

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Thanks, this table shows the pressure ratings versus temperature for 50/50, 95/5 and for brazing versus the pipe types and diameters.

14

The mounting for the custom Oasis XD300-12 Compressor was a challenge.

On the port side of my 2000 Searay 380 Sundancer there is a built-in ice maker, behind a door, under the counter. When that ice maker is removed it exposes an inaccessible, unused volume. That is the location for the compressor.

This volume does not have any airflow. It has only one hidden exterior air opening, permitting air ingress or air exhaust., but no natural cross flow.

The floor of this volume is directly above one of my 143 gallon gasoline tanks, so it is not possible to bolt the compressor to this surface. I designed and created a mounting plate for the compressor, that is secured to the floor using lag screws around the perimeter.

The mounting plate is made of 3/4" plywood, coated w/ epoxy for protection. I also added a 1" polyester webbing strap to retain the motor to the mounting plate.

The system must be very secure, especially when the seas get rough.

Volume Before Modifications

Initial Dry Fit

Mounting Plate

Motor 1" Polyester Webbing Strap

Motor Secured by Webbing

Compressor Installed

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Part of the compressor modification includes the addition of high-volume forced fresh air cooling onto a custom-designed / fabricated cylinder head plenum.

The sides of my boat has teardrop-shaped openings to permit engine combustion air ingress and also for blower exhaust. The tip of that opening was modified to add a custom-designed / fabricated 4" flexible vent hose support.

The partition wall separating the compressor volume from the volume above the engine compartment was modified to drill a 4" mounting hole to mount the Shurflow 4" 220 CFM Yellowtail Blower to that partition wall.

The blower is currently wired to run when the compressor runs. An in-line fuse is used to fuse the blower to the specified 7A, instead of the 200A feeding the compressor motor.

This forced air cooling works GREAT!

There is plenty of fresh exterior air flow dumping across the cylinder head. I can grab onto the head while the compressor is running and it is not hot.

Exterior Air Inlet

Exterior Air Inlet w/ 4" Vent Cut Modification

Exterior Air 4" Vent Support

4" Partition Hole

Suction-side Vent Hose

Exterior Air Inlet

Pressure-side Vent Hose and Blower

Custom-designed Cylinder Head Shroud

Exterior Air Inlet and Cylinder Head Shroud

16

The mounting location for the compressor is not level. It slopes down slightly from the compressor end to the motor end.

As-such, when the oil level ball sight glass window is set / checked when the compressor is level, it shows as empty when installed in the operating position.

There were several ounces of Oasis Compressor Oil added to make the ball sight glass centered when mounted. The ball sight glass shows over full when the compressor is level.

The compressor oil level is easy to check by sliding out the ice maker to permit this visual inspection.

Ball Sight Glass When Mounted in Operating Position

Ball Sight Glass When on Level Surface

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One of the modifications was to remove the internal lip on air fittings, to maximize flow.

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The compressor was modified to permit using a new dash panel switch, matching the existing dash panel switches, to control the compressor.

The compressor includes a low-battery cutoff circuit w/ a low battery indicator lamp on the exterior of the compressor. My mounting has the compressor hidden, so that indicator lamp is useless for my installation.

A custom circuit was designed and created that connects to the existing lamp points on the circuit board, but instead drives an indicator on my new dual-indicator dash switch.

Component Side Low-Voltage Circuit Board

Solder Side Low-Voltage Circuit Board

New Dual Indicator Compressor Dash Panel Switch - Power and Low Battery

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Did you do all of the work yourself? I’m asking because the job is very thorough with things done that the average installer would ignore in favour of getting the job done quickly, getting your money, and moving on. I’m also asking because I’m pretty darn handy by most people’s standards, but I can neither sweat/solder copper nor make custom circuit boards – and I’m envious of someone who has developed those talents in addition to being able to use CAD, handle airflow planning, be handy with pneumatics, yadda yadda.

A lot has gone into the project – and it shows. The one thing that surprised me was the use of copper line in something that’s going to be battered by waves; I’d have expected the use of air brake lines and fittings (which handle vibration very well, I’ve found) in an environment that’s tossed about as much as a boat.

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Yep, except for the CAD and aluminum welding, all me, thank you.

The copper is retained by stainless cushioned Adel clamps across the length.

The copper was selected for the supply side because of all the fittings required for the valves, switch and regulator. The tank and copper are all secured to the same structure.

The load side is 300 PSI rubber tubing w/ some copper at the valves.