Photo Tachometer??

[jpsmith1cm]

Is anyone using one?

I have been looking at some of the less expensive models as a method of preventive maintenance for fan motors?

Basically, trying to predict failures.

Am I off base or would it be worth the $50 or so for one?

[beachtech]

i am interested in buy one too :)

hopefully someone wil be along to help us both :)

and i am willing to spend more than 50 if there is a good and dependable one that will help me on the job :)

[marvin]

been using the fieldpiece stand alone tach for about 6 months.
would guess it is within 1 % accurate. not a fieldpiece fan but would buy another if i needed one

[beachtech]

been using the fieldpiece stand alone tach for about 6 months.
would guess it is within 1 % accurate. not a fieldpiece fan but would buy another if i needed one

i am not a fan either, but you like it that much. i didn't know they offered a tach. i gotta go check it out :)

[boldthvac]

Use the Testo 465 Digital Tachometer - spendy $185:eek: but good.

[jpsmith1cm]

Is the concept of using the tach for predicting failures sound?

[WhoIsThat?]

Is the concept of using the tach for predicting failures sound?
My thought exactly; how is motor failure connected to motor speed?

I'd think insulation resistance or bearing noise or motor vibration or brush condition or start-switch contact resistance or winding temp. are all much better predictors of imminent motor failure.

[beachtech]

yea, a 2-4 thousand dollar IR camera would prolly be better for detecting early failures. but i think a $185 non contact tach could also aid in detecting premature failures as well. maybe the both combined would be a nice combo.

but if you're looking at a direct drive fan motor and it's rated @ 1075 but only moving 950, would you suspect something is wrong? or if that motor doesn't spin up to 1075 in a reasonable amount of time.

or say a belt driven blower set up. continuing maintenance, date and record the rpm's on paperwork or the cabinet and this record of info can help indicate when it's time to change the belt, or maybe early fan motor failure :)

just a couple ideas i can think of that may be good uses of such a tool :)

i dunno :confused:

[jpsmith1cm]

My thought was that as the motor condition, particularly with small, sleeve bearing or unit bearing type motors, speed slip would increase as the motor deteriorated.

Maybe I'm just angling for a reason to buy a new gadget.

Nahhh.

:D

[DesMech]

This is the one I use for TAB work. Not cheap though.

http://www.grainger.com/Grainger/items/1PX61

[fcs]

I ask a Motor and Controls and he said you need to remember when you open the Air Handler to get your reading you changed the load

With that in mind I stop looking at them.

[beachtech]

I ask a Motor and Controls and he said you need to remember when you open the Air Handler to get your reading you changed the load

With that in mind I stop looking at them.

but if you're keeping a record of the same load and situation... i dunno

i understand that, and that's a very good point :)

what about condenser fan motors? you can get a good rpm reading on them and still operate them at thier proper load condition. would be kinda neat to see if rpm is affected with a wet OD coil or a panel off. that would kinda prove the point of a indoor blower theory :)

[fcs]

but if you're keeping a record of the same load and situation... i dunno

i understand that, and that's a very good point :)

what about condenser fan motors? you can get a good rpm reading on them and still operate them at thier proper load condition. would be kinda neat to see if rpm is affected with a wet OD coil or a panel off. that would kinda prove the point of a indoor blower theory :)


My wife going to kill you now I want to buy one again

[beachtech]

My wife going to kill you now I want to buy one again

lol send her my regards. which one are you looking at?

i kinda like that fieldpiece one posted earlier. i am not so sure about that extech one. drop me an e-mail and i will let you in on one of my tool buying secrets ;)

[fcs]

Testo Pocket Pro 460 Optical Tachometer - RPM Meter

As for the Extech I found their stuff doesn't stand up to banged around in your tool bags very well.

However their price is always so good and they have a lot of features I can't help but to get sucker again:rolleyes:.

I don't have ANY Feildpice.

Whats been your experience with them

[beachtech]

Testo Pocket Pro 460 Optical Tachometer - RPM Meter

As for the Extech I found their stuff doesn't stand up to banged around in your tool bags very well.

However their price is always so good and they have a lot of features I can't help but to get sucker again:rolleyes:.

I don't have ANY Feildpice.

Whats been your experience with them

i have been using fieldpiece for the last 5 years, and am a little dissapointed with the HS36 meters that i have used the last two years. the SC76 meters that i have retired worked great for the year is uses them. i'll prolly buy the testo too.

i too have heard some not so good news about extech and how fragile they can be in a bag or even occasionally droped.

i have a couple testo meters and really like them. the accuracy has been spot on since i bought them. the size of the meters are a little small IMO

i haven't cruised the net yet to see which one i may fall victim too lol

[allstar08]

Every time that I think I need one I usually don't get one. I have worked on some Quincy compressors that were rpm sensitive and that is about it. A big ex. fan from time to time, but rpm has never been used as a maintenance tool. I would rather use amps, and temp, or sound and touch.

[Carnak]

I use a testo 465

I used one by Monarch, was good too.

[beachtech]

Every time that I think I need one I usually don't get one. I have worked on some Quincy compressors that were rpm sensitive and that is about it. A big ex. fan from time to time, but rpm has never been used as a maintenance tool. I would rather use amps, and temp, or sound and touch.

WHOA

i am not thinking that because you have checked RPM's that amps, sound and the touch test should be neglected.

i am thinking about one more test and or check i can do to ensure that i have completely and competently checked that motor and or belt drive, or whatever it may be that spins or moves at a measurable speed :)

[beachtech]

I use a testo 465

I used one by Monarch, was good too.

i guess the 465 is an older model :confused:

i found a 460 model on jim's site. at 180 ish i am going to go ahead and add that to my tool list for 09' :)

[Carnak]

i think the 465 is one step up the ladder

[JWB]

We got some old tools and refrigerant from an old school guy that retired. One of the more interesting tools he had was a mechanical rpm gadget. Didn't think much about it until you guys ran this thread. Now I gotta dig through the shop and find it...........

[bkcalhoun]

I ask a Motor and Controls and he said you need to remember when you open the Air Handler to get your reading you changed the load
.


That's true and with direct drive the motor will slip more, but with belt drive the amps change, but not the fan speed.

[beachtech]

That's true and with direct drive the motor will slip more, but with belt drive the amps change, but not the fan speed.

very interesting info :)

thanks :)