help with power supply box

[cztexas 0]

I just bought Altrox altv248175ul3 and thinking it is good choice (made in usa). But the output voltage is 29/34 vac instead of 24/28 vac.

I knew it should be a little bit higher than its rated value due to power loss. But 29 vs 24 seems too high for me. I just do not to fry my camera. I did try them on my cameras. It works. But my concern is will it shorten the camera's life?

Does all Altrox PSB has similar setting or I just got a "bad" Altrox?

Thinking to return it, but kind of worry to try another Altrox.

Need your suggestions on 24vac power supply box.

 

Thank you!

[Soundy 1]

There's nothing wrong with that box; those are normal readings depending on the type of multimeter you're using, and the actual input voltage.

 

"Rated" voltage generally refers to RMS voltage of the sine wave. 24V RMS means a sine wave with about 34V peak voltage. While higher-end multimeters will give proper RMS readings, most cheaper ones rectify the voltage and then measure the DC output... except the waveform is bumpy and not steady. So, you end up with a reading somewhere between 24V and 34V, depending on how much filtering the meter puts on the signal.

 

The input voltage will have some effect as well, since an AC power supply is not regulated, but simply consists of a step-down transformer. In the case of a 120V-to-24V supply, that would be a 5:1 step-down... but if the input voltage varies, the output will vary accordingly.

[cztexas 0]

There's nothing wrong with that box; those are normal readings depending on the type of multimeter you're using, and the actual input voltage.

 

"Rated" voltage generally refers to RMS voltage of the sine wave. 24V RMS means a sine wave with about 34V peak voltage. While higher-end multimeters will give proper RMS readings, most cheaper ones rectify the voltage and then measure the DC output... except the waveform is bumpy and not steady. So, you end up with a reading somewhere between 24V and 34V, depending on how much filtering the meter puts on the signal.

 

The input voltage will have some effect as well, since an AC power supply is not regulated, but simply consists of a step-down transformer. In the case of a 120V-to-24V supply, that would be a 5:1 step-down... but if the input voltage varies, the output will vary accordingly.

 

I totaly agreed with what you have mentioned. I am a Electrical Engineering in Power System.

But the problem is, the 29 VAC is the true-RMS, measure by Fluke Multimeter, not the cheap one:)

The primary voltage is 123VAC.

And also, as measuring the output of transfomer, I measured in both situation: no load and with load.

The best scenario I got is using 100 ft CAT5e, connected to my 13w camera, the end terminal voltage will drop to 26.7, which is fine. But if I change to CNB VCM-24VF, which only requrie 3w (=very low current), the voltage drop will be less than that. I did not try it.

[cztexas 0]

Could any owner of Altrox altv244, Altrox altv248 or Altrox altv248175 measure their actual voltage right out of box? I want to know whether the 29/34 is normal or not.

 

Thank you so much~~~~

[Soundy 1]

Something doesn't sound right if you're getting 2.3V loss at 13W over a mere 100'. Even using a single pair for power, you shouldn't see more than half of that.

 

And if your RMS readings are that far off, that would at most indicate a faulty or improper transformer in that unit... not that that's a bad model line. I've used dozens of Altronix power cans over the years, both 24VAC and 12VDC and even one or two 24VDC, never had an issue.

 

Anyway, I wouldn't worry about the CNBs... if memory serves, those will actually accept pretty much anything from 10 to 30V, AC or DC.

[cztexas 0]

Something doesn't sound right if you're getting 2.3V loss at 13W over a mere 100'. Even using a single pair for power, you shouldn't see more than half of that.

 

And if your RMS readings are that far off, that would at most indicate a faulty or improper transformer in that unit... not that that's a bad model line. I've used dozens of Altronix power cans over the years, both 24VAC and 12VDC and even one or two 24VDC, never had an issue.

 

Anyway, I wouldn't worry about the CNBs... if memory serves, those will actually accept pretty much anything from 10 to 30V, AC or DC.

 

I trusted your memory and I did try the CNBs. It works, but the voltage is still around 28vac with 100 ft cat5. Everyting looks normal except some resisitors on PCB inside the camera are really hot.

I know this box is not bad model line since Altronix has been proved good quality here. So do you suggest me to try anothe one or should I keep this one (I got this one from ebay, the seller accepted returns)?

 

Thank you.

[Soundy 1]

Ahh, good ol' fleaBay. Are you sure that's the original factory transformer in that thing?

 

I'd recommend returning it for a refund and buying one from a reputable dealer.

 

Or, just DIY - transformer and fused breakout board, there's really not much to it.

[cztexas 0]

Ahh, good ol' fleaBay. Are you sure that's the original factory transformer in that thing?

 

I'd recommend returning it for a refund and buying one from a reputable dealer.

 

Or, just DIY - transformer and fused breakout board, there's really not much to it.

 

 

Well, it looks like the original transformer~~~

 

Any reputable dealer do you recommend, online? ~~~

[cztexas 0]

Thank you. I need 24vac power supply since my ptz only took 24ac. I bought my dvr and 2 cnbs there. But they do not have AC power supply box.

[Soundy 1]

Can always run your CNBs on 12V and just use an individual 24VAC transformer for the PTZ

 

There are lots of other brands besides Altronix as well - Enforcer, Pelco, etc. etc. But again, I suspect the issue (IF there is one) with your existing unit is the seller, not the brand name.

[cztexas 0]

Can always run your CNBs on 12V and just use an individual 24VAC transformer for the PTZ

 

There are lots of other brands besides Altronix as well - Enforcer, Pelco, etc. etc. But again, I suspect the issue (IF there is one) with your existing unit is the seller, not the brand name.

OK, got it. I will try another one.

 

Thank you for your quick help.

[Thumpin455 0]

KEEP IT! I also noted that on my Altronix HubSat 8D UTP Transceiver Hub with Integral Power, instead of 24/28 VAC, am getting 27.5/31.5 VAC output

 

Tested with 2 cheap multimeters, a Craftsman and a Greenlee, and both measured the exact same. Also noted about a 0.2 voltage drop at the camera end over about 100ft Cat5e using 2 pairs for power.

 

Bought it new and thought about sending it back but was anxious to start my install. Have been using since March no problems with 4 Pelco IS151 w/htr's and 1 Samsung SCO-2080. I think you will be good with the higher than stated voltage with decent cameras that should have decent auto sensing input circuits.

 

The transformers do have a slight low freq hum but inaudible when the box is mounted in a closet with foam isolators.

 

Paul

[cztexas 0]

KEEP IT! I also noted that on my Altronix HubSat 8D UTP Transceiver Hub with Integral Power, instead of 24/28 VAC, am getting 27.5/31.5 VAC output

 

Tested with 2 cheap multimeters, a Craftsman and a Greenlee, and both measured the exact same. Also noted about a 0.2 voltage drop at the camera end over about 100ft Cat5e using 2 pairs for power.

 

Bought it new and thought about sending it back but was anxious to start my install. Have been using since March no problems with 4 Pelco IS151 w/htr's and 1 Samsung SCO-2080. I think you will be good with the higher than stated voltage with decent cameras that should have decent auto sensing input circuits.

 

The transformers do have a slight low freq hum but inaudible when the box is mounted in a closet with foam isolators.

 

Paul

Well, already return it. Mine is like 28.9/34.5 (due to my input voltage is 123vac). I will keep it if it could below 28, with 100ft cat5e, it could drop more.

I guess this is for 7.5A max, so the output voltage is much higher for open load.

I bought ALTV248, which is 4A max. Hope this one will function well.

The cameras are much expensive than PSU. I prefer to pay more attention with it.