Test pressure control

[1960flh]

[color=#000000]Tony;

As always this is the value of the members on this forum

[bruce]

Just add in a vacuum break valve and set it higher than your desired max depression but lower than the burst point of your panels.

Been a back-burner project to build something simple using a nut, bolt, spring, gasket and a plate.

[Tony]

[Tony]

Ha-ha Rick, the old hands here can smile knowingly.

Newcomers to flow bench construction often never give this aspect any thought at all. The reaction is almost always YIKES !!!!! the light goes on in their head, and they see the danger immediately.

[riga team]

Hi boys! Who can that application will find...
http://item.express.ebay.com/Industrial ... Speed-Cont
rol-Rheostat-potentiometer-motor-AC_W0QQitemZ300038752926QQihZ020QQptdnZMotionQ20ControlQ2
cQ20DrivesQ20Q26Q20MotorsQQddnZIndustrialQ20SuppliesQQadnZElectricalQ20Q26Q20AutomationQQc
mdZExpressItem ANATOLIJ

[riga team]

Hi boys! Who can that application will find...

[apex944]

Anatolij
Do a search in Google for: "Router Speed Control"



There are many. Remember, our AC system here is 110v.

[riga team]

my blower motor 3 fase... i look VARIABLE FREQUENCY DRIVE !!! Prompt: which best
????? [url=http://cgi.ebay.com/Allen-Bradley-Adjust-AC-Motor-Drive-Cat-1334-DJB-7-5HP_W0QQitemZ250074617090QQihZ015QQcate
goryZ42894QQcmdZViewItem#ShippingPayment]http://cgi.ebay.com/Allen-B....Payment[/url] [url=http://cgi.ebay.com/Magnetek-503-DS316-380-460V-7-5-10HP-AC-Drive_W0QQitemZ320005086366QQihZ011QQcategoryZ4289
4QQrdZ1QQssPageNameZWD1VQQcmdZViewItem]http://cgi.ebay.com/Magnete....iewItem[/url] [url=http://cgi.ebay.com/AB-Allen-Bradley-AC-Drive-1336-B010-E0D-FA2-10-HP-10HP_W0QQitemZ250076500567QQihZ015QQcate
goryZ42894QQrdZ1QQssPageNameZWD1VQQcmdZViewItem#ShippingPayment]http://cgi.ebay.com/AB-Alle....Payment[/url]

[Tony]

Anatolij,

The first Alan Bradley one looks to be a fairly old design, and only goes up to 60Hz output, so personally I would not touch it.

Being able to go to 80Hz, or 100Hz, or even more.... is particularly useful with an air blower. You could mount your blower direct onto your motor, run it at 120Hz, and not need to use the 2:1 step up pulley you have. That would be more efficient, more compact, with less noise and vibration.

The second Magnetek VFD appears to be a very modern Chinese design. Just looking at it, it is identical in appearance to the Chinese Teco VFD I am using here myself right now. Both can be set to run all the way up to 400 Hz, and it has an absolutely huge range of software programming options. If it is like mine, you will be extremely happy with it.

The second Alan Bradley also appears to be a fairly recent model going up to 250 Hz, and far better than the first one.

I would bid on the last two myself, and be happy with either. These drives cost very roughly around $1,000 US dollars new for a 10Hp unit.

Make absolutely sure the instruction book comes with it

It took me most of one day to read the 130 pages of instructions and program it to do exactly what I wanted. Without the correct software programming book you will be in real trouble.

[riga team]

Thank's Tony. seller from e-bay didn't answer me jet about operating sistem. i found new Alan Bradley 22C-D012N103
AC DRIVE POWERFLEX 400, 380-480V, 3PH, 12A, 5.5 KW, IP20, FRAME C from 0 till 400 Hz in my country per 860$ with guarantee and technical help. expensive choose, but i think will must stopped on this variant. if i understand right make frequence from 60 till 300-400 Hz, i can take rpm from 2800 till 5000 rpm and more. How such rpm and Hz will influence on engeene.
best regards Anatoly

[Tony]

These VFDs are still very slowly coming down in price, and the performance and features provided is constantly getting better.

So a new one may not cost that much more than a very old one, and you will know there is not going to be anything wrong with it. Being able to get help, and having the proper instruction book is vital in setting it up. The software menus, and choices available, are complicated to understand and program correctly. That is why I preferred to buy a new unit myself rather than buy secondhand.

Your 7Hp motor can be run up to a much higher speed, and still supply the full 7Hp. It is just that the torque falls off in proportion to the extra speed. A much better way to do it than with a step up pulley. A maximum speed limit, and maximum amps load limit can be set in software, so it cannot run away from you and blow up. The rpm can automatically be set to ramp up with a gentle acceleration, so there is no sudden current inrush to blow fuses or trip circuit breakers. The motor can be sized right up to the full maximum capacity of the available power, without any danger of ever exceeding the maximum at turn on.

The only other thing is the aluminium bars fitted to the slots in the motor's rotor. At some very high rpm, the motors rotor will fly to bits, but twice rated rpm always seems to be safe, and probably a little bit more than that with some slight risk may be possible.

Just make sure your motor bearings are suitably rated. If the motor is fairly old, some new bearings may be a very good idea, and they are not expensive. For instance, with the 15Hp motor I have here, the original bearings fitted to the motor were rated for continuous operation at 5,600 Rpm. Mounting a big blower right onto the motor with some suitably rated bearings and a VFD, is a very neat way to solve a whole lot of problems.

[jsa]

[quote="riga team"][/quote]
Anatoly,

Yes it will vary output frequencies anywhere from 0 to 400hz depending on your set parameters.

I'd have a concern with running a standard induction motor designed for 50 or 60Hz up to 400Hz. I suspect they may not be designed to run up to nearly 7 times the rated frequency.

A typical 50hz 2 pole motor runs at around 2900 rpm and a 60hz motor around 3500rpm. At 400Hz thats up around 11600rpm. The rotor cage and rotor itself could very well fly apart at this speed.

Check with the motor supplier what the maximum shaft speed can be or use a motor designed for that speed.

[riga team]

Thank's boys! I think my 3 pole antique engeene (made in USSR) have 30% of supply. When this engeene was making, masters didn't grudge metal. But i didn't take chances more 4000rpm. I recieved answer about Magnetek 503 DS316 7.5-10HP.( It comes with instruction manual, As far as the the software is concerned they didn't offer Firmware up dates for the 503 series drives the drive is operational and software works like it is supposed too.) Big diference between 300$ and 800$. I have big temptation take this one Magnetek.
Anatoly

[Tony]

I agree, a normal 60Hz motor probably should not be driven beyond perhaps 120Hz.

The reason many drives work at up to 400 Hz these days, is that the military commonly use 400 Hz three phase power in airborne and some warship applications. There are some extremely well built, compact, and powerful surplus motors around that can be run from a VFD at 400Hz.

But more importantly, these more modern higher frequency VFDs usually have a lot of extra very sophisticated features that can be useful. The ability to reach 400Hz in itself is probably not.