Amps Vs. Harrison

[E31Committee]

We are designing a new pumper tanker. We have decided to go with either an Amps or Harrison Hydraulic generator. If anybody uses either of these generators, please let us know your feelings.
e-mail to: BDvfdFF32@firehousemail.com

Thanks!

[wegmo]

Look at the Ambient Temperature rating. Harrison is rated at say 10kw @ 130º. You will find Amps at a lower temperature and Smart Power only at 86 degrees, meaning the 10kw may only make 8600 watts of power when performed in the UL test.

[ScottDixon]

Greetings!

In response to your message, there are several points we would like to clarified:

First, all AMPS eHP [electronic High Performance] series generator SYSTEMS (pump, reservoir, and generator assembly) - are not just rated - but designed, tested, and rated for 120 degree F. ambient temperatures. We are in the process of having the new eHP system parameters certified by an national independent laboratory. It should be noted the generators are rated 180° Celsius - not Fahrenheit - which is Class H insulation design. This is a whole other generation . . . that will set the standard for hydraulic generators in the industry. The eHP series is in full production.

Second, in regard to lower generator output, as temperature increases on any hydraulic system, the hydraulic fluid viscosity decreases, cooling air density decreases, resulting in changes in hp delivered to the motor . . . requiring pump adjustments to maintain adequate flow to maintain the required frequency. Of course, after the adjustments are made, cooler ambients may result in high generator frequency, requiring additional adjustments. Some - on their own volition - to get around the constant adjustment of the pump chose to declare the generator a lower wattage but far lower than the generator capacity - it just "detuned." This is true with most closed-loop hydraulic systems - not just generator systems. Solution? Make the necessary fine adjustments.

Third, one of the features of the new eHP series is that instead of having to do the manual pump adjustments required to maintain rated output, the system adjustments are done automatically . . . electronically. This automatic digital electronic control also features an integral SAFE-start (TM) system that takes all the wonderment out of the question, "Do I, or do I not need a soft start?" No need for a soft-start kit! It ALWAYS starts SAFE and SOFT.

Start a conventional hydraulic generator under load . . . and/or at high engine rpm and you can expect catastrophic internal and external damage to the system (pump, motor, generator, etc.) due to sudden high torque spike, etc. This is compounded if soft-start kits are not installed or installed incorrectly. It is necessary that the generator and components 1) be installed correctly, 2) electrical loads be balanced, and 3) the system be operated correctly - if catastrophic damage is to be avoided. Moreover, damage to system components (internal/external) are usually not covered by warranty.

Fourth, of course, any system must be installed correctly - according to the generator manufacturer's recommendation. What about operating conditions? Well, the new eHP series is designed to be "more forgiving" of varying operating conditions - one can start the generator under load and at high engine rpm. We've been testing this new generator series for a year with numerous field trials - you will be pleased with what you see. It ALWAYS starts SAFE and SOFT. This is a whole other generation . . . that will set the standard for hydraulic generators in the industry.

Finally, Coming Attractions. We expect our "military grade" xHP [extreme High Performance] system to be released during 2002. It is being designed, tested, and rated to operate in environmental extremes.

Thanks for the opportunity to respond and to set the record straight. Call us for detailed information.<br />Sincerely,<br />Scott Dixon<br />AMPS<br />281-240-2555

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[pafirefighter]

I know of a company that went to a Harrison mid-production because of supply problems from AMPS. Just another thing to check out. <img src="confused.gif" border="0">

[ScottDixon]

1. Thanks, the7tuwer! We watch these forums to make sure people are getting correct information, our reputation depends on it.In addition it gives you a direct contact to us.<br />You are going to be amazed at the performance of the new eHP Series (Electronic High Performance)<br />I see that you are taking delivery this year of 9 more...did you know that your fire department is eligible for something special? Please contact me directly for details, 281-240-2555.<br />2. Greetings, Pafirefighter.net<br />I am guessing by supply problems you mean delivery. I am not aware of the particular situation you mentioned. Our current lead time is running 4-5 weeks after reciept of order. Most OEMs order well in advance of their needs, so delivery should not be a problem.<br />In case of an emergency where a unit must be expodited through production we do our best to jump through hoops in order to make it happen! In fact we just recently completed a RUSH retrofit on a truck at our facility(yes we do generator installations too)and we have a ladder truck from a MAJOR fire department in here next Monday.<br />If you have a special rush delivery requirement, call me.<br />Sincerely,

Scott Dixon<br />AMPS <br />281-240-2555<br />marketing@a-m-p-s.com

[Jim Otwell]

As a matter of practice, I do not normally make comparisons with competitors, however since you asked and AMPS made their pitch first, I felt it was a good time to make an exception.<br />Harrison was the first and it is where AMPS and most of the rest initially began. Our primary market has been the oilfield and our generators were designed for their environments, which are much harsher than the fire industries. You as a consumer benefit from the higher standards we are required to conform to. The quality of a hydraulic generator is determined no differently than any other product. It’s based on the quality of components, design and workmanship. I do not think anyone, including Mr. Dixon, would dispute Harrison uses major components (alternator, drive motor, heat exchanger, etc.) of a much higher quality than that of AMPS. Design is another issue and unlike components, is quite subjective. In order to keep this as short as possible I will respond to Mr. Dixon’s post above. As far as workmanship, I am sure AMPS has great employees that take pride in their work and do it very efficiently. <br />“First”, all Harrison generators are and have been for the past thirty years, manufactured with Class “H” insulation. I would disagree that just because AMPS started using generators with Class H insulation, they have now set the standard. Among other benefits, class H insulation will prolong the life of generator, but under no circumstances would it be possible for ours, or any system, to operate at 180° Celcius ( 356°F) as suggested above.<br />“Second”, although ambient temperature does affect the hydraulic oil temperature, the heat exchanger designed into the system should be adequate enough to stabilize the temperature of the oil thereby controlling fluid viscosity and frequency fluctuations. I am not aware of anyone who does, or would accept constantly making pump adjustments due to temperature changes. There are conditions where the generator has to be de-rated because it is unable to carry the rated wattage. High ambient temperatures and altitudes are two of the most common reasons. Harrison de-rates ALL generators based on the original OEM ratings. For instance, when you purchase our 10kW, it is actually rated a 12.5kW continuous duty alternator by the OEM. You pay for a 10kW but get a 12.5kW. We do this to compensate for high ambients and altitudes. <br /> “Third”, Soft Start? We have never required one on our generators. Some designs may require it, ours does not. If a design does require a “soft start” or other method to engaging other than a hot shift pto, the question to be asked is why and not how.<br />Mr. Dixon’s blanket statement, “start a conventional hydraulic generator under load or high rpm and it will cause catastrophic damage”, is completely false. Conventional wisdom will tell you that it is not good for a generator to be started under load regardless of the manufacturer or whether it is driven by gas, diesel, or hydraulic. Can it be done? Yes. Will it cause catastrophic damage? It shouldn’t and maybe on other systems it might, but not ours. You can engage and disengage a Harrison at any engine rpm without doing any damage to the pump, motor, or generator and it can be done without a soft start. It’s the way we have been doing it for over thirty years.<br />I appreciate the fact AMPS is improving their products and wants to advertise on these forums. However, I am disappointed by some of the misinformation being offered. This is a relatively small industry and most apparatus manufacturers can shed light on the questions AMPS has raised. I don’t ask you to take my word for it, just ask the Apparatus builders before you buy.<br />Thank you for your forum.<br />Best Regards,<br />Jim Otwell<br />Harrison Hydra-Gen, Inc.

[DrKAMPS]

Hi! Isn’t this great! A great exchange of information! I wish to comment in a general way . . .

First, we would be the first to agree that Class H has been around a long time and is nothing, in itself, new. However, that was not our point. Please note that we stated in all caps, SYSTEMS. Indeed, we should have expanded on the topic. The point here is that even though the generator as a separate item may be rated Class H insulation, its use in a SYSTEM is important. I think we all agree on that. However, NEMA Class H insulation is 125-180 C degrees temperature rise above 40 degree C ambient for the generator windings! Generator windings. High winding temperatures (measured with imbedded detectors in the windings) are generated (no pun intended) by current in the windings plus ambient. Our point was that AMPS – we can only speak for ourselves – uses Class H design and is seldom a problem at normal ambients. Is it possible for the generator windings to "see" extreme temperatures. Very. In any case, prolonged extreme high temperatures effect insulation and bearing life and can have a detrimental effect on generated current (kVA) due to resistive (primarily) and inductive effects. No mystery. See our comments below on temperature.

Second, the reference to pump adjustments. Sure, hydraulic generators should have adequate heat exchangers for cooling. And viscosity changes at higher temperatures - even with adequate cooling - resulting in lower hp to drive the motor. A good design encompasses these parameters. Our point was related to ambient temperatures far in excess of the generator industry standard ambient reference (NEMA MG -1-1998:105 degrees F).

Sure, one could derate - and not mess with any fine adjustments - due to higher temperature (not enough hp; hence the need to derate) but at lower temperatures one would see WIDE unavoidable variance in frequency or speed REGULATION (per ASME PTC 26 standard definition). Why? The viscosity of the hydraulic fluid varies widely over a temperature range of 32 degrees F to 120 degrees F and directly impacts the ability of hydraulic system to turn the pump at desired rpm. We agree on that I believe. Bottom line: derating works but it simply means that frequency regulation (due to ambient temp change) would be different or “sloppy’ between the two ambient extremes - an additional parameter that should be required performance parameter for a ‘derated’ unit. This is a general condition of hydraulics at temperature extremes that leaves three choices: 1) derate and accept wider regulation than normal ambient, 2) do not derate and make fine adjustments to maintain tighter regulation, or 3) intervene in some way to directly control regulation. No straddling the fence here since all choices are mutually exclusive – no middle ground. That’s pretty straight forward, I think.

However, we merely wanted to point out that our approach is to intervene and simply employ electronic ischronous frequency regulation that eliminates the wide frequency droop variances. What this means is that in the range from 'freezing' low to 'sizzling' hot high ambient temperatures (32 degrees-120 degrees F), the frequency regulation would remain constant and not exceed +/- 0.85 percent or +/- 0.5 hertz. It’s fact. This is what we were trying to state in as simple terms as possible.

Third, as far as generator capacities, AMPS generators are rated in as most generator sets worldwide. Designed, tested, and rated at 120 degrees F. There is no derating for temperatures ranging from 32 degrees F to 120 degrees F. All ratings are continuous duty (100 percent duty cycle).

Fourth, as far as the electronic control of starting conditions. Yes, we do it safely, without stressing the hydraulic components or generator. Yes, we do that. The eHP series is designed, tested, and rated for high speed (2500 rpm) engagement with approval of clutch and pump manufacturers.

No soft-start? From my old days at the original Harrison when we pioneered hydraulic generators, it did not take long to find out that high speed engagement of a conventional hydraulic generator subjects the system to extreme torque stresses (high inertia with system components and hydraulic fluid) and can result in catastrophic damage to components.

It seems that Harrison may have solved the high inertial stress problem . . . great. We did also. We would hope that you would join with us in recommending this precaution:

Caution: Anyone purchasing hydraulic generators should ask the generator supplier for a ‘high speed engagement’ approval or certification of both the clutch and pump manufacturer. We recommend it.

Starting the generator under load? On SOME engine-driven generators that used to be true and may still be true. I can attest to that since I used to be in the conventional engine-generator business. However, in recent years we find major RV generators offering this feature. Well, conventional wisdom is no longer conventional! It’s the day of computers and electronics. Welcome to the next generation. We do it soft and easy. There are no hydraulic component or generator stresses when starting the eHP generators under full rated load.

In conclusion 1) we've explained the NEMA Class H rating in detail - should be no misunderstanding, 2) we've clarified extreme temperature frequency effects and our solution: ischronous regulation, 3) we've clarified generator ratings typical in the industry - should be no misunderstanding, 4) we've commented on high speed engagement and recommend obtaining pump & clutch manufacturers approval, and 5) we've pointed out that starting generators under load is perfectly safe while some generators can not be started at all under load.

Finally, in summary, we have merely responded to questions and comments here - as we are doing now. Misinformation? Well, that’s stretching it a bit. Maybe not enough information – if I may speak for Scott Dixon - since Scott tried to avoid techno-speak.

I am sure that Scott Dixon would NOT agree (neither would I) that Harrison uses higher quality internal components than AMPS. One does not see AMPS making such direct charged statements here about any competitor. (I believe this forum has a policy that states ‘harm the reputation of another product or manufacturer’ is not permitted.) We do not blantly promote our products but we do talk about what we know – AMPS products – in response to comments and questions about AMPS or its products. You may have noticed. We’ve avoid such baiting . . . and will not comment other than we use name-brand hydraulic components (Sunstrand, Volvo, Rexroth, Aeroquip, Honeywell, Fire Research meter, to name a few). Interesting . . . after AMPS made the Fire Research meter standard it was soon adopted by other generator suppliers. The proprietary electronic control now used on AMPS eHP series is also manufactured for AMPS by Fire Research. We wonder when others will follow AMPS and offer electronic controls. ?? This is what we mean by ‘setting the standard and raising the bar’ – solutions that take hydraulic generators to a new level.

We appreciate the opportunity to clarify these things. We hope the above information shed some light on the comments and questions. Educational. Nice to have the opportunity to clarify our comments.

See you in Tyler, Texas later this month, Jim?

Dr. John Karonika, Ph.D.<br />VP/General Manager<br />Advanced Modular Power Systems

[ 01-10-2002: Message edited by: DrK ]</p>

[ScottDixon]

I would like to say thanks to the E31 Committee for starting this forum. It has had many readers. <br />We appreciate the opportunity to answer your questions directly.<br />Scott Dixon

[SCOOBY14B]

We were looking into putting AMPS on our seven new engines but decided against it after hearing several stories of the cages coming apart. Dont know what truth there was to it but we decided against it. I also was very leary when Sugar Land FD won't use them after having problems. It is not good PR if you cant get your hometown FD to use your product.

[JBROWNL8]

Scooby14B-<br />I work for Sugar Land on E1. What problems are have you heard that we are having. My engine has an AMPS unit and also our Ladder 4. I have not heard of any problems with the AMPS products on either of units. We are having problems with Ford and the Aurogen unit on our Squad 4. Other than that, our AMPS units are working great. I am curious at who was your contact here at Sugar Land.

Jerremy Brown <br />Sugar Land FD

[JBROWNL8]

Hey Scooby14B, have you come up with a name of your contact here in Sugar Land. Could it be just a hoax? Since I havent had a reply in some time I would assume so.

[Mary Ellen]

As a general question to any of these manufacturers; can these generators be added to existing apparatus? What is the cost range? We have a 1990 International and a 2001 International and are somewhat interested.

[fcvfd]

....can these generators be added to existing apparatus? What is the cost range? We have a 1990 International and a 2001 International and are somewhat interested.

Try calling them. $9K to 20K.

[stevecook2001]

Mary Ellen,

In response to your question, yes. Hydraulic generators can be retro-fitted to existing apparatus.

I cannot comment on other manufacturer's pricing, but our LIST prices range from approximately $7,900.00 to $20,000.00. Our product line goes from 6kW to 30kW with some models offering DC output options.

If you would like more specific information, please give us a call. If you have the engine and transmission information, we can give you the full details of the generator's ability in that application.

Thank you for your interest. We look forward to hearing from you.

Steve Cook
Technical Services Manager
281-240-2555 phone
281-240-8571 fax
steve_cook@a-m-p-s.com

[FIREKRAUT]

Just for everyones information, ONAN has just come out with their own hydraulic generator. It is now available in 6 and 8 kw, the 10 kw will be available by mid year. The model # is CMHG 6000 or 8000.