Pelco Spectra III power supply question

[Charles_Heraver 0]

I have a question concerning the Pelco WCS 1-4 power supply.

 

It is powering a Spectra 3 SE PTZ camera.

 

When using the PTZ commands via the DVR, the camera usually doesn't respond correctly. It will start OK, then "go crazy" and ultimately it looks like it is rebooting. Pressing the " - " IRIS button usually starts this. The camera will move back and forth, up and down, zoom in and out, etc. then reboot. It does its power on maiden spin correctly.

 

I've replaced the back box, unplugged the fan / heater, and swapped in a spare, new dome drive. I've also replaced the coax cable with a pre-made BNC cable. The problem still persists.

 

The camera is wired to the 24VAC "A" tap on the supply. There is #18 AWG wire going about 20 ft up the pole to the camera. I moved the wire to the "B" tap and the camera's operation is greatly improved. According to the sticker in the power supply, the A tap should work fine. I have 120VAC coming in and approx. 25.5 VAC on the A tap.

 

I'm tempted to try the highest voltage "C" tap but am somewhat reluctant to keep increasing the voltage.

 

Any thoughts or suggestions would be most welcome, as we have a couple of these cameras doing the same thing at different sites.

 

Thank you very much!

 

Charles Heraver

[survtech 0]

Is that all the WCS1-4 is powering? Is the Spectra III in an environmental dome?

 

The reason I ask is that the WCS1-4 is rated to supply 4 amps. A Spectra III in an Environmental back box with heater "on" draws ~70VA (approximately 3A @ 24VAC) while with heater off it only draws ~25VA (approximately 1A). At 3A draw, the nominal voltage of the WCS1-4 will probably drop to closer to 24V. In addition, while 18 gauge wire should be sufficient for 20 ft., there might be a problem like broken strands, etc. Are you sure it's 18 gauge?

 

All Spectra Series domes will stop working if the power drops below ~18V. But you don't want to feed too high a voltage to the dome drive. Even moderately high voltages will cause excessive heat. Really high voltages (greater than 30VAC) would likely fry the dome's power supply. That's an issue you need to take into account with environmental housings. It is possible that voltage would be in range with the heater "on" but become excessive with heater "off" due to power supply and wiring voltage drops under the higher loads.

 

I've also seen the reverse. One client complained that his outdoor Spectra worked fine during the day but shut off at night. On further investigation, he was in a cold climate and was powering an environmental Spectra with approximately 150 feet of 18 gauge wire. During the day, the wire's voltage drop was within range but at night when the heater came on, voltage dropped way down. The solution was to re-run power using 12 gauge wire.

 

The other possibility is the dome drive itself. Spectra III's had power supply problems so Pelco released a modified power supply as a "DD53KIT". It can be obtained from TLS Electronics (aka Time Lapse Supply) for approximately $170.00 (http://www.timelapsesupply.com/pelcospectraiii.html).

[Charles_Heraver 0]

Survtech,

 

Thank you for your reply.

 

To the best of my knowledge they are Spectra 3 SE. I am pretty sure it is an environmental dome housing, but will get part numbers and try to verify on my end. The Pelco power supply is only feeding one camera. There is a heater board mounted in the back box mounting bracket.

 

The power cable is a Belden shielded cable, and it is marked as #18 AWG. Tomorrow I intend to pull some #14 THHN up the one pole to rule that out. The idea of broken strands could be true, and I suppose the installers could have kinked or damaged the Belden cable during the install. I took a Fluke 41B to check the AC in and out, and the sine wave looks fairly decent.

 

I have already replaced several of the original power supplies with the DD53KIT from T.L.S. We also bought a complete dome drive from T.L.S. to use in troubleshooting.

 

In you opionion, are these good cameras, or do they simply "wear out" after a period of time. Ours are approaching 10 years old, and the original installation wasn't the best.

 

Thank you again for your help, I really appreciate it.

 

Charles Heraver

[survtech 0]

Charles,

 

Spectra III's are excellent PTZs. We have ~120 Spectra II's, III's and IV's (in process of replacing all Spectra II's with either IP or Spectra IV's) and, other than the power supplies, feel that the III's are/were the best of the group. We also do our own repairs(a major reason for "retiring" Spectra II's is parts discontinuance). It is possible the Spectra IV's pan bases will hold up better in our hot climate but otherwise the Spectra III's and IV's develop similar problems.

 

One major negative about Spectra IV's - firmware. Pelco's early firmware had bugs and their update tool doesn't work most of the time. We tried updating firmware on a couple and gave up because the results were disappointing. Spectra III's never had real firmware issues.

[Charles_Heraver 0]

Survtech,

 

I really appreciate your help.

 

I have a Spectra 3 SE dome drive that is giving me fits. Powering it on a test rack (back box and mount, power supply and video monitor) the drive does nothing.

 

I swapped in a new camera assy, and then I can see the lens zooming in and out during its normal boot up. After the lens goes in and out a couple times I hear relays clicking, as if the dome drive is trying to pan and tilt to finish its boot up sequence. There is no movement from either motor. I swapped both motors, then the slip ring, then the receiver/driver board, remembering to short the reset pins on initial power up. None of this has changed anything. The parts are all from TLS, so they should be good. Am I missing something?

 

I tried moving the D.D. myself, hoping it might "make up" those 2 prox/position switches, but nothing.

 

 

I have yet another dome drive, fresh from TLS, and it seems to operate MUCH better after I turned the Auto Iris OFF with the on-screen programming. By much better I mean it responds to the PTZ commands almost flawlessly, where as before it was very sluggish, to the point of sometime not doing anything.

 

Thanks again for any insight you can provide.

 

Charles Heraver

[survtech 0]

Charles,

 

I just talked to my PTZ Tech and he confirmed my thoughts. You say you've replaced the camera head, motors, slip ring and receiver/driver board. Did you replace the power supply (DD53KIT)? Did you replace the original camera with the same model?

 

99% of the problems with Spectra III's are with the original power supply board. While it can be repaired, it is usually better in the long run to just replace the entire board with a DD53KIT. Also be aware, if you replace the camera (rarely needed in our experience with Spectra III's - much more common with Spectra II's) you must replace the original camera with the same model. If you substitute a different camera model it would require a different firmware. Only the Spectra II's allowed that due to their socketed firmware chips. Spectra III's and IV's have soldered firmware chips that are not easily replaced.

[Charles_Heraver 0]

Survtech,

 

The camera heads I am swapping are the same model number. The only difference that I can tell is they are the "B" stock from TLS. These are in the environmental metal dome housings.

 

The dome drive I'm frustrated with already has a DD53 KIT but that was done 2 or 3 years ago. I can certainly try a new DD53KIT and see what that does. I can't think of anything else to do at this point.

 

Like you said, the original power supply boards were failing, and looking brown burnt.

 

Right now I have 3 dome drives that are dead. Two have the problem above while the third does not always power up and configure correctly. Sometimes it says CONFIG FAILED, other times it passes the config, but the video is coming in and out of video loss. Same parts above were replaced with no change.

 

Please don't think I'm ranting on you, I'm just not getting these cameras. I really do appreciate your replies.

 

Charles Heraver

[survtech 0]

Charles,

 

We have not had one DD53KIT fail so I'm at a loss. It appears you've replaced nearly everything we can think of. From your list:

 

1. Camera Ass'y - rarely fail in Spectra III's and IV's. Common failures in Spectra II's, especially the Sony BCBW cameras.

2. Pan and Tilt Motors - Have never seen one of them fail.

3. Receiver/Driver Board - Occasional failures on all Spectra series.

4. Slip Rings - Occasional failures on all Spectra series.

5. Power Supplies - Occasional failures on all Spectra series. High failure rates on Spectra III's but we've never seen a DD53KIT fail.

6. Plastic parts: Pan base, tilt arm, locking tabs - all get brittle from SoCal heat and crack. All models.

7. Belts - Both belts have to be replaced with age. Usually when we replace the Pan Base and/or Tilt Leg.

 

We've found that TLS' recommendations have usually been spot on. You might give them a call. My Tech usually talks to Jim Moore when he gets stumped. Incidentally, Jim's original company was Moore's Electronics in Tiburon, CA but I believe he sold it. That's who we used to send our Spectras to before we started repairing them in-house but after paying Pelco's exorbitant repair charges. Average cost to repair dropped from $400-$500 (Pelco) to $300-$400 (Moore's) to $200-$300 (in-house).

[survtech 0]

Sample of recent parts orders we've placed:

 

VK-S454N Hitachi Camera head for Spectra 4

PA05-0085-01A2G Spectra 3 Backbox PCB

MF00-7050-003C Base enclosure Spectra 3

DD53Kit Spectra 3 Power Supply

PA03-0004-5028-B Spectra 3 Logic Board

VK-S454R-B Hitachi Camera Head for Spectra 4 PTZ

 

Test Bench:

 

 

 

Note the long cable coming from the back box. We made that up ourselves with wire and a male and female connector. It makes servicing and testing a lot easier.

[henyuanwh 0]

power supply http://www.china-pbx.cn

[Charles_Heraver 0]

Survtech,

 

That is a pretty impressive set up you have there!

 

I made a simpler one, using a power supply, back box and BB mounting bracket on a piece of plywood. The video out goes to an Ideal video tester. If the dome drive powers on OK, I hook a coax to a spare DVR input and test the PTZ from there. Works for us here, as cameras are only a small part of what I'm involved with. We are a municipal drinking water utility in northern Illinois.

 

We decided to just buy a couple refurbed dome drives from TLS. That should gets things done and operational while the rented lift is still here, and more importantly before winter. We'll probably see about sending the hulks back to TLS for repair.

 

So thank you again for your help and insight. I appreciate it.

 

Charles Heraver