THE NEW "GENERATOR of DEATH"

On December 1, 2007, we received the new 20 KW 3 phase generator set, which replaced the old "Generator of Death", PU-708 US Marine surplus generator. The old unit developed a serious problem during the September VHF Contest. It ended up having to be shut down early Sunday evening with a destroyed air blower that wreaked havoc on the engine. A fix looked problematic, so we opted for a new machine instead. When the old generator had been rebuilt at a Marine Depot in 1976, someone had forgotten to put locking hardware on the two shaft nuts in the air blower. After we ran it for awhile, these nuts started to loosen, causing a slow loss of air pressure. The actual source of the problem was not detected and we started having engine overheating issues for a long time. The overheating started in 2004! We did not detect the real problem for a long time. this all culminated on Sunday morning of the 2007 September VHF contest, when the engine lost power and was belching black smoke from unburned fuel. We ran the engine on Sunday until about 8 PM when we were hearing clanking noises and shut it down. The engine was trashed at that point, as the blower had vibrated itself to pieces. A bearing had destroyed itself after the locking nut fell off the shaft. The metal blower debris was blown into the cylinders. So it was time for a new power unit.

Shown below is the generator shed with the front removed so we can side the new machine into place on a recently poured cement pad. A friend provided a good sized tractor in case we needed some extra muscle to move the generator. Everyone is dressed for winter, as it was 14 degrees farenheit, with a wind blowing at up to 30 mph.

The generator appeared at 1 PM. We picked it up that morning, in Hermon, ME. about three hours away. The generator was built by CMD Power Systems. Al, NS1O provided the Dodge RAM 2500 diesel 4 WD truck. It made short work of hauling the 1500 lb unit up the 4 wheel drive hill road to our contest site. Having a large 4 wheel drive vehicle made all the difference in this job. Here you can see it as it emerged out of the woods on the hilltop. (See below) The road is 4WD accessible only and winds about 1/2 mile through the woods from the main road.

We then backed the truck up to the generator shed and started rigging the planks and cement blocks to slide the 20 KW generator onto the pad, which is visible just behind Larry, K1CA, inside the shed. We really lucked out with the delivery, as it snowed heavily the following day and the hilltop became inaccessible, even with 4WD, due to heavy snow. The snow remained all winter. With a total snowfall of ten feet, it would have been impossible to haul the new generator up there until about Mid May of 2008!!

To get the 20 KW generator started on its way off the truck bed, we applied some heavy planking and cement blocks to support them. The next idea was to use a come along and a heavy nylon strap to persuade the generator to start moving off the truck. Once it started moving we needed all hands to steady the unit and keep it centered on the planks.

Larry, K1CA lines up the cables in preparation of dragging the generator down the plank ramp and onto the cement pad. K1OR is helping Larry, K1CA hold the webbing while he hooks it all up. The interested bystander is Ed, my neighbor, who helped us with the manpower.

Once we got the big "Mamou" sliding, gravity helped it along and pretty soon it was sitting on it's pad and ready to be hooked up to the AC power buss. Visible in the photo, from left to right are: K1WHS, K1OR, NS1O, Ed Sardinha our next door neighbor, Jonathan Sauers my son in law, and Dana Beal, the guy with the big John Deere tractor.

Final adjustment required to get the 20 KW "Little G.O.D." centered on the concrete pad. A few metal pipes and pry bars worked wonders. The new genset has no switching capability, so we added a large 3 phase contactor on the wall of the shed, and hooked up the electrical connections with some short runs of #4 copper wire to the contactor. The output of that contactor is connected to the heavy cables that run to the ham shack about 100 ft away. The contactor is needed so that the shack remains disconnected until the generator is making full output at 60 Hz. Only then will it be connected to the main buss and circuit panel. After watching this new unit perform, we are inclined to give it a new name that indicates a more refined and docile machine than conveyed by "Generator of Death." This unit does not roar or belch smoke. It can't be heard 1/2 mile away. It does not seem like a beast at all. It just purrs along sitting there on its concrete pad. I ran it for awhile in the January contest, and with a 144 MHz 8877 amplifier, it seemed to work reasonably well with a light AC load. The voltage regulation was reasonably good, and it also provided ample electric heat to warm the shack!

These generators are built by CMD Power Systems, in Hermon, Maine. They have various options available and many sizes from 15 KW up to about 100 KW. This particular unit has an electronic speed governor module on a 2.3 liter Cummins diesel engine for precise engine speed control. In addition, there is a solid state voltage regulation module on the Marelli 20 KW 3 phase generator end to hold the voltage constant under load. A third module acts as a controller for all of the engine functions and protective circuits. It senses oil pressure and water temperature and provides emergency shutdown in case of high temperature or low oil pressure. In addition, it will sense a high engine speed, overcranking at startup. It also provides an automated start sequence for glow plug heating and engine start. We are "stylin'" for sure if this thing actually works. Now all we need is a good AC ammeter panel to check power loading for each phase. I obtained some AC current transformers and will rig something up on the wall to monitor the current on each AC leg. You want to be sure that you load each phase equally. When that is all done, we can get back to working on improving the ham station! We have decided that having good reliable AC power is the most important facet of running a good contest station. Without it, as we were in September of 2007, and you have nothing. Boy are those words prophetic as you read on.....

So the first big test for the CMD Power Systems generator was the June ARRL VHF contest. It failed miserably! No sooner had we started it and started to load up the transmitters when it just shut down with an overheating engine failure. From June 14th to July 10th, I had to fight with CMD to even honor their "labor" warranty. A representative of CMD Power Systems informed me that there was no labor warranty. After some verbal confrontations, they finally agreed to come and look at their malfunctioning engine. The repair tech who came on July 10th noted that it overheated in five minutes with a 19 KW load on the generator windings. This was not good. A further inspection revealed that someone had never put a thermostat in it, or someone had removed the one that was there. Of course the repairman did not bring a thermostat along on an overheating repair call. (?) It is hard to say, but the thermostat may have been left out of the factory built engine! I agreed to install a new thermostat to save them a trip back. The new part arrived from CMD on July 17 and of course it was the wrong part. I am now of the opinion that CMD Power Systems is not quite on top of their game in generator sets. I would think twice before ever consider buying anything from them again. So far this Summer (2008) I have missed the June VHF Contest, and the CQ Worldwide VHF Contest. I guess I'll be missing a few more at the rate they are going. Just getting reliable AC power turned out to be difficult as long as CMDl Power Systems was involved in the process. They finally did send the correct part by the beginning of August. I installed the part myself. The same problem re occurred. The engine would not stabilize at any operating temperature. As I piled more power on, the engine temperature started to climb. With 12 KW load, it was running at 208 or 209 degrees F, which is way too hot. The manual specifies that 212 degrees will damage the engine. I figured that a few more KW load and it would shut down from overheating. The repair people from CMD arrived on August 8th and determined that the unit is incapable of delivering 20 KW of power. It could not even deliver 16 KW without shutting down. It looks like it is only good for about 8-10 KW at reasonable engine temperatures around 190 degrees. So now I am stuck with a brand new generator that was never properly engineered, and never tested. Hard to believe but that is what has happened. Needless to say, I would hesitate to recommend a CMD power plant. If anyone asks me I will tell them to run the other way! In the meantime, while this is all going on, the contest station is inoperative. For their part,CMD Power Systems agreed to come and haul the unit away and re work it to solve the overheating problem. I think they called it "re-engineering". I usually try to get things working properly the first time before I deem it ready, and sell it for almost $10,000.00..

The generator was picked up on August 18, and taken back to the CMD shop. I was assured that it would be returned before September 10th in time for the September ARRL VHF Contest. They tore into the unit trying to figure out why it would overheat. They replaced the fan with a more aggressive one. (It looks like it came off a P-51 Mustang!) Next they tried a bigger radiator. Next they changed out the entire engine. Only after all of this did they determine the problem. The Cummins engine has a coolant inlet on the right side, while their radiator had its output flange on the bottom left. This was bad as it was difficult to run a hose easily. Their solution was to remove the flange and re mount it on the right side of the radiator. What they did not realize was that the radiator had a convoluted water path that snaked down the right side, then up the middle and then back down on the far left side of the radiator core. When they moved the flange, they shunted almost all of the cooling capacity of the radiator. No wonder the thing was overheating! When they realized their error and relocated the outlet flange, it immediately started working just fine. They returned the whole assembly on September 10th and slid it back on the cement pad. We ran it about 60 hours that weekend starting on Friday. If anything it was running too cool! Now I have to block a portion of the radiator so as to allow the engine to come up to a reasoanable temperature. The hottest it got in the September contest was 174 degrees. Most of the time it was at 155 degrees F which is a bit too cold for a diesel engine. It sure is fun to pay all this money and then feel like your purchase is a guinea pig in an experiment! The good news is that it is running reliably, with good AC power. We had all the amplifiers running in September along with two air conditioners, and had no power issues with an 18 KW load. There is no way this thing will overheat now!

The scary thing about all of this is that there are a few other similar generators also made by CMD, that are identical to this one, that were shipped around the country with the incorrect radiator. They will all overheat in the same way as mine first did. If it has the 2.3 liter Cummins engine. I guess I really got a bad unit. The good news is that CMD did eventually fix the problem. They even delivered it back onto my concrete pad on the hilltop. That is no small feat by itself as the above pictures illustrate. I must aso add that the components that are used in the generator are first rate and capable of stellar performance. My gripe is that the unit was not properly load tested before it got to the end user. That oversight caused me untold grief.