Tuesday, January 21, 2014

Emergency Engine Starting

I recommend learning how to hot-wire-start marine engines. Our old monohull, a WestWind38, we briefly had a bad starter button and I had to learn how to start the engine without it. Diesels are easier to start than gasoline engines because all they need are compression, fuel, and air while gasoline engines also need high voltage spark to the spark plugs. I'll focus on diesel engines in this post because that's what is normally used in modern auxiliary sailboats.

You will need a good starting battery to turn over the motor to get it started, but electricity is not needed for the engine to run (unless it has a shutoff solenoid that needs power to allow the engine to run). To turn over the motor, you need to power the starter motor. The starter motor will normally have a big solenoid mounted on its side ('Solenoid' in the photo). There will be a big red wire from the battery connected to a bolt on the solenoid ('Battery Wire' in the photo). There will sometimes be another big wire connected to the solenoid, which provides the connection to the starter motor ('Starter Wire' in the photo). In other cases, this connection is an internal connection between the solenoid and the starter motor. There is a third, smaller wire that is the connection from the ignition for activating the solenoid ('Activation Wire' that's yellow/brown in the photo). There is a second photo from 2carpros.com that shows a clear view of the back of the solenoid.

Volvo MD2040D Engine Starter and Solenoid Components

Starter Solenoid, courtesy of carpros.com
The ignition switch at the helm supplies 12v on the Activation Wire (Starter Trigger Terminal in the photo to the right), causing the solenoid to be activated. Contacts internal to the solenoid close, connecting the battery wire to the starter wire, and causing the starter motor to turn.

Of course, the diesel has to have the engine stop disengaged, because that stops the flow of fuel. The Volvo MD2040 engines on LUX use a mechanical stop cable that causes the high pressure pump to stop injecting fuel into the cylinders, causing the engine to stop. Newer engines that don't have stop knobs will typically use a stop solenoid that is electrically activated.  If your engine uses one of these solenoids, you will need to hot-wire it to allow the engine to run. Learn whether your solenoid is activated to allow the engine to run or if it is activated to stop the engine. In the first case, you'll need to hot-wire the solenoid to allow the engine to run. In the second case, you'll need to hot-wire it to stop the engine. Or you may be able to pull the stop lever by hand - it depends on how the stop solenoid operates.

There are two approaches you can use to starting an engine when the starting system at the helm doesn't work. In both approaches, you must have a good starting battery. Make sure that the stop cable or solenoid is not engaged. Make sure that the engine is not in gear and the throttle is at idle setting.

WARNING! WARNING!

When you hot-start an engine as I'm about to describe, you and your various body parts and clothing are very close to machinery that will soon be rotating. Getting a T-shirt caught in the alternator or water pump belt can yank you into the engine compartment and cause serious injury. Keep all body parts and clothing away from the engine. And watch out for the wire you're using to jumper the starter.

When you start the engine, your head is going to be close by a suddenly very noisy engine. Be prepared for the noise and don't react in a way that imperils you.

Method 1

If the starter solenoid is good, all you need to do is jumper from the Battery Wire to the Activation Wire on the solenoid. I use a good quality (16 gauge wire or greater) alligator clip jumper wire. Clip to the Battery Wire and touch it to the Activation Wire terminal on the starter solenoid. Make sure that you're clear of all rotating parts because the engine will turn over and should start. You'll also get a few sparks as you make contact. Note that the ignition does not have to be 'on' for the engine to start and run. This is like a lawn mower that can start unexpectedly when the blade is turned by hand. On LUX, the Activation Wire is an insulated terminal, so I have to remove it from the solenoid to gain access to the solenoid Activation Terminal.

Method 2

In some cases, you may have a dead solenoid. Either the coil in the solenoid has broken or the contactors are worn out and not passing the battery's power to the starter motor. In this case, you use a short, fat cable (#2 or larger) to jumper from the Battery wire to the Starter Wire. You're using the wire as a replacement for the big copper contactor that's in the solenoid. You may need two hands to properly hold the cable and make a firm contact between the two connectors on the solenoid. You'll get more sparks with this method, because there is a lot more current involved.

With both methods, don't leave the jumper wire connected for long. It should only be used long enough to get the engine started. The alternator should be charging if it wasn't damaged in whatever caused the starter solenoid to fail.

If you have an engine that has a compression release lever, and there is little battery power left, you can activate the compression release, start the engine turning over with the battery power you have, then release the compression release to get the engine started. This procedure would be useful where the alternators are also damaged and are not able to charge the batteries.

By learning how to hot-start an engine, you are a safer mariner, able to make landfall with engine power even if something like lightning takes out most of the electrical system.


  -Terry

Sunday, January 5, 2014

Renewing the R&C Logo

Like most older Leopards, the R&C logo on the hardtop support had seen better days. Much better days. When Chris Smith (formerly of L47 Tribe), offered to get new logos from R&C, we jumped at the opportunity. $60 gave us two new logos. We opted to not do the L40 paw-print on the cabin side, mainly because we already had the big LUX name on the mainsail bag.

We used a razor scraper (not a razor knife!) to remove the old logo. Go slow and keep the razor flat against the gelcoat or risk nicking it. Where the vinyl of the old logo had been attached was nice, white gelcoat, contrasting with the weathered gelcoat all around it. This was both good and bad. It gave us something with which to align the new logo, but it was raised above the surrounding gelcoat, which would make adhering the new logo a challenge. You can barely see the shadow of the old logo outline in the photo to the right.


We started by aligning the new logo, with backing still in place, and attaching it with blue tape. Undoing one edge of the blue tape and folding back the new logo gave us access to the area where the logo was going to be attached. We then wet sanded the gelcoat to provide a smooth surface. The first sanding was with 320 grit with a backing block and lots of water. When the raised surfaces were removed, we graduated to 600 grit, then 1200 grit. Finally, we applied some rubbing compound to provide a glossy finish. The surface was then cleaned with alcohol to remove any sanding and compound residue.



We sprayed the logo area with water, the backing was removed from the logo, and it was pressed down. Using a squeegee, we pressed out any bubbles. A couple of bubbles wouldn't come out, so we used the razor scraper to gently pop them and the squeegee to smooth them out.

We waited a few minutes to give the vinyl time to adhere to the gelcoat, then removed the covering, slowly pulling it back on itself at a sharp angle, making sure that the vinyl remained on the gelcoat. The result is a nice looking replacement for the old, faded, and mostly missing logo. The whole process took about two hours one day while we were lounging around LUX, anchored next to Baker's Bay Marina in the Abacos, Bahamas.

Another example of cruising: boat repairs in exotic locations. ;-)


-Terry

Is That Holding Tank Full Already?

Monitoring tank usage is important on LUX. We often are traveling in no discharge areas and have to get a holding tank pumpout done before it is full. The float sensors on the holding tanks aren't great. Calcium buildup quickly makes them ineffective. We needed a better way to monitor holding tank capacity and decided that it would also nice to be able to monitor water tank usage, though it is relatively easy to just open the forward lockers and look at the water levels.

There are a number of tank monitoring systems around. Getting one that works for a combination of water, waste, and fuel is rather interesting. It needs to work with potable water, corrosive waste, and flammable liquids. Two systems seem to get the best marks: capacitive sensors or pressure sensors. 

The capacitive sensors work only on non-metalic tanks. Two strips of conductive tape are applied to the side of the tank and the sensing electronics is calibrated to determine the range of values that correspond to the volume of liquid in the tank.

Pressure sensors work by using a dip tube that extends from the top to nearly the bottom of the tank. Either a manual or automatic pump is used to pressurize the tube until bubbles come out the bottom. The pressure is then read as an indication of the amount of liquid that is covering the tube.

Float switch-based systems typically don't work well, particularly in waste systems. Bits of gunk (that's a technical term ;-) ) and calcium buildup will quickly inhibit the float switch operation.

After looking around at some systems, we decided on the Profile Series 8-tank monitoring system from Ferriello Sales. <http://ferriellosales.com/> It can monitor up to 8 tanks and can accept input from a variety of sensors, including our existing fuel sensors, a propane tank sensor (for tanks equipped with a sensor), as well as capacitive sensors. The system can handle weird sized tanks, which is a plus on boats. The display can show a summary of all 8 tanks or a higher-resolution display of each tank's capacity. Alarms can be set for full or empty levels. Alarms can be disabled at night, as determined by a photo sensor. Dennis, the owner, has received a number of accolades from people regarding the superior level of service that he provides. Our experience was similar. The system cost, including wire from West Marine, was about $450.

We intend to monitor six tanks: two each of water, waste, and fuel, even though the fuel monitoring is redundant with the fuel gauges at the helm. We don't have propane tanks with sensors, but that's a possibility for the future.

The display is mounted at the top of the navigation station and provides good visibility. The display is in the process of being mounted and is sitting on the counter in front of the open DC electrical panel. The blue tape at the top of the nav station is used to mark the cutout and to protect the gelcoat during the cutting operation. We neglected to get a photo of the completed installation - something to do on the next trip to LUX.

We have reserved space above the Shore Power panel for the genset control panel, which will be installed this summer, 2014. This will put all the AC equipment panels together for ease of monitoring.

The holding tanks were the first to get sensors. The process is easy to follow and works well. We used nearly 100ft of wire to connect both holding tanks and expect to use that amount for the water tanks. The sensors require three connections: Ground, Power, and Sense. The Power and Sense connections have to come from the display. We were able to use the ground wire from the old tank "full" sensors at each tank, so we only needed to run two wires (Red=Power, Blue=Sensor) from the tanks to the display. We used quick-disconnect electrical connectors so that the tanks can be easily removed in the future.

Calibration required emptying the tanks, then filling them, which we did with water at the next pumpout. The system works well, allowing us to monitor all 8 tanks with one glance as well as more detailed views if we're filling water and fuel tanks.

We ran out of wire after doing the holding tank sensors, so we'll add water and fuel monitoring when we return to LUX.


-Terry

Saturday, January 4, 2014

Getting Juiced Under Way - Battery Charging

LUX has three battery banks: the 600AH house bank, a starboard starting battery, and a port starting battery. The original electrical system uses an automotive solenoid (a relay) to connect the house bank to the starting battery of whichever of the engines is running (or both, when both engines are running). The charging system relies on the alternator internal voltage regulator to prevent overcharging the batteries. The alternator internal regulator is not a smart three-stage regulator (bulk, accept, float); it simply limits the output voltage to the peak battery voltage of lead-acid or AGM cells, about 14.6v on LUX. The alternator output goes directly to the starting battery, which is connected to the house bank when the alternator is running. On the Leopard 40 Owner's Manual schematic, the R output of the alternator energizes the solenoid coil, causing the solenoid to close whenever the alternator is running. Not shown on the schematic is a suppression diode across the coil connections, used to absorb the reverse voltage spike that results when the energizing current stops.

When both engines are running, the respective solenoids are activated and all three batteries are charged from both alternators. The internal regulators on the alternators rarely have exactly the same output voltage, causing unbalanced charging current as the batteries reach full charge. In a discharged state, the battery voltage is low enough that both alternators will typically charge at near their rated capacity. But as the batteries become charged, the voltage approaches that of the regulator. When this happens, one alternator will be providing more current than the other. On LUX, it was normal to see 60A on both alternators when the house bank needed charging, and 20A on one alternator and 5A on the other once the batteries were fully charged.

One of our solenoids died and we were faced with replacing it. We could replace it with another solenoid or we could use something smarter (better?). I was not very happy with the existing solenoid system. It connected the starting battery to a discharged house bank, causing a current surge as the starting battery and alternator attempt to charge the house bank back to a fully charged state. This causes stress on the starting battery as well as on the solenoid contacts. If the house bank is discharged 50% (12.2v) and the starting battery is fully charged (12.6v), the resulting current surge can be quite large. While starting batteries are built to provide large currents for short periods, they are not built for deep discharge, which is basically what is happening. It might take several hours for the charging system to bring the combined battery bank back up to 12.6v.

If engine maintenance is being conducted that prevents charging the starting battery, it may wind up with insufficient power to start the engine. In this case, it would be sufficient to start the other engine, then use a jumper wire to activate the solenoid on the dead starting battery in order to charge it from the running engine. It would take a while for it to charge because the house bank will need to be brought back up to a high enough state of charge to start the dead engine.

In another scenario, it is possible for the ACR to cycle. Blue Sea Systems has a good explanation in their article Preventing Cycling in Battery Combiners

The above scenarios tell me that the design could be improved. The ultimate installation would be a 3-stage charge controller on each engine. Balmar and Ample Power both provide systems that would work well, at a cost that's $1000 or more. The Balmar will need two of Max Charge controllers, a Center Fielder to control both chargers, and two Duo Charge units to provide charging of the starting batteries. The alternators will probably need to be modified to provide the connections for the charge controllers to control the field voltage, which is how they regulate the output.

An alternative is to replace the solenoid with a Blue Sea Systems Automatic Charging Relay (ACR), also known as a battery combiner. In this system, the ACR functions similarly to the solenoid. However, it is smart enough to connect the starting and house bank only when the voltage of either is above the trigger voltage for some amount of time. For the ACR, it is 13.0v for 90 seconds on either battery, see ACR Explained.

I decided that the best way to reconfigure the system was for the alternator on each engine to charge the house bank first and have the ACR connect the starting battery when the house bank reached the ACR threshold. In this scenario, a discharged house bank gets full alternator output until it reaches 13.0v for 90 seconds. The ACR will then close, connecting the starting battery to the house bank. The battery voltages are closer to each other and a relatively small amount of current will cause the starting battery to quickly reach 13.0v. This has less effect on both batteries and avoids the cycling problem referenced above.

Another benefit of this configuration is that either engine will charge the house bank. When the house bank reaches the ACR's 13.0v threshold for 90 seconds, both starting batteries will be connected and a single engine can charge all three batteries.
NOTE: Adjacent to the ACR is the shunt that is used to sense alternator output current and is shown on one of the meters at the helm.

The small gray electrical box next to the solenoid/ACR contains the relay that controls power to the engine compartment fan. Since the alternator R output is no longer used, the relay must be connected to the engine ignition circuit. This means that the engine compartment fan runs when the ignition switch is turned on. With the old system, the relay that drives the fan wouldn't be activated until the alternator's R output energized the relay.
WARNING: One of the fuses and holders in this box was melted, which I replaced with a similar fuse holder. It uses automotive style spade fuses. It was not clear what caused the fuse and holder to get hot enough to melt but not blow the fuse. It is advisable to periodically check these fuse holders. Also, the box is old enough that the edges of the cover broke off. I replaced the screws with 2.5-inch screws that screw into the backing plate.

What about the Victron charger? I connected its main output to the house bank. It has a second output, which is limited to 4A for charging a starting battery, but we have two starting batteries. With the main output connected to the house bank, it functions just like the engine alternators, charging the house bank first, then adding the starting batteries when 13.0v is reached.

Update 5 Jan 14:
I've been asked for a schematic of the change. I was able to use the L40 owner's manual schematic to show something of the wiring change. The left picture is a close-up of the upper left part of the complete engine/battery schematic before the modification. I've identified the solenoid and the fan relay. Disconnect the wires from the old solenoid, noting the wire numbers. I've found that the numbers match what's on the schematic. If your boat doesn't have labels on the wires, then mark them yourself with tape and a marker. Mount the ACR. Connect the House bank wire and the alternator output to one lug. Connect the Starting battery wire and the F-3 (fuse for Eng Blower) wire to the other lug. It doesn't matter which lug, because the ACR senses on both lugs and will close when either of them is 13.0v or greater for 90 seconds. You can disconnect the wire from the F-5 fuse since it is not needed for the ACR. You can wrap the F-5 wire connector in tape and heat shrink and wire-tie it back on itself. You could remove the wire from the system if you have the inclination and time. It travels in one of the black covers, which is why I decided to simply cover it and protect it from shorting. F-3 is found in the gray box and I think that F-5 is also located there - trace the wiring to make sure. Make sure that the Eng Blower fan relay still has a ground, which was connected to one side of the solenoid's coil. In the second photo that shows the ACR with connections, there are two big wires and one small red wire on the left lug. There is one big wire on the right lug. The left lug is connected to the alternator output and to the house bank and to F-3. The right lug is connected to the starting battery.

Summarizing, you're going to swap the locations of the Starting and House wires where they connect to the ACR and you're going to not use the wire from F-5. The schematics below are before the modification.


  -Terry