After all the discussion about the Mean Well power supply, I thought I'd post a final update.

I installed it this morning, and it's out there pumping 1 Amp into a 20W resistor box. I want to be sure it maintains voltage (and doesn't trip the GFCI) while operating in the cold.

Here's a photo on my website showing the installation: <http://astronomy.mdodd.com/observatory.html#PowerSupply>

I appreciate all the opinions and suggestions this thread elicited. I'm looking forward to running the AP1200 from a reliable power supply.

--
Mike

Mike Dodd
Louisa County, Virginia USA
http://astronomy.mdodd.com

Thank you Peter for the video link. I plan to tackle the encoder installation next Thursday. I know who to contact if I stumble.

Hello Marj,

Mike,

Good idea about "isolating " your Mean Well power supply with wood and a plastic enclosure, so you no longer (?) have a leaky ground return to the GFCI, from it.

If the "Euro Safety Regulations", as recently noted by Rolando, require tying power supply DC Returns to chassis/earth ground - dumb idea, unsafe for electronics even with a nearby storm just miles away - and the chassis ground on the 120 AC side of the power supply case and power cord's earth return (third pin) is also tied to house neutral in the fuse box through plumbing or copper ground rod, then why wouldn't the GFCI not trip, when it senses even a few milliamps, (or perhaps just micro amps), supplied by the CPx controller's serial port housing? That's true for many other controllers anywhere on the scope besides just AP's). In such case, the (slightly) leaky chassis ground return is tied to the GFCI circuit protected socket.

The GFCI would naturally trip to protect you from being (potentially) electrocuted by electronics with a chassis ground tied to the pier.
Seems logical. Probably nothing you can do to prevent it, except replace the GFCI outlet for the pier, with a non-fused one. However, your home fuse box panel might also be wired with GFCI breakers. It probably isn't, or you would have a room full of lights drop out every time you power up the telescope electronics, using a normal outlet. GFCI breakers are very sensitive, if they do their job right.

You can likely prove the possibility of the pier chassis leaking current to your GFCI protected AC power cord, supplying your telescope. Using an ohmmeter , check the resistance (continuity) between scope electrical system and GFCI supply - on the unpowered telescope - by touching the probe to the bare serial port screw on the CPx, and the other probe to the earth safety ground pin in the AC socket at the telescope. A meter with a "continuity buzzer" would be easier to use than looking at a reading.

A few milliamps of chassis current won't hurt you, but it is reassuring that the GFCI would protect you from a major short circuit from something at the pier. But, the GFCI can be a nuisance for typically minor amps from pier equipment.

Joe Z.

Does the Default.mlm file have pre-defined meridian limits? I saved new meridian limits on my installed default.mlm file by accident. If default.mlm has pre-defined limits I'd like to restore them. I moved the overwritten default.mlm file to another directory then re-installed APCC but the new default.mlm file wasn't in it's directory. 

Thanks
Claude

On 11/8/2019 9:55 PM, Don Anderson via Groups.Io wrote:

Hi Mike
Did you try the Alinco on another outlet?

No; the one that tripped was the one powering the pier equipment, so that's the one I tested.

No matter. I have the Mean Well mounted on a board, and enclosed on three sides with a plastic shield that extends over the ends, so I'm ready to use that one.

--- Mike

Wonder if anyone is using or planiing to use a NiteCrawler focuser/rotator with this scope? Is it doable?

Hi GTO gang!  Some good detective work by some smart people at Lowell Observatory (Thanks Jim C.!) has led us to a probable solution to WiFi dropouts when using Sky Safari, Luminos etc.

It appears we have been looking at this the wrong way.  We were blaming weak or corrupted signal from our WiFi module, and couldn't reproduce the problem here.  Instead, it appears that our signal may actually be too strong and may be overwhelming the smart devices' WiFi hardware. 

For right now, if you are having WiFi dropout issues, please fold your antenna into its little cubby on the GTOCP4, and then try not to let your smart device get too close to the GTOCP4.  Try to keep the device a couple feet from the GTOCP4.
Please give us feedback on your results.  If this does indeed turn out to be the issue, then we may be able to fix it permanently and more elegantly.
Thanks in advance for any feedback you can give!

Howard 

Richard, please contact me at AP if you would like to update your database.  

ANYONE  with a GTOCP4 who needs to update their keypad database, please give me a call.  Our engineer added keypad programming support to the lower COM port and to the USB COM port so that keypad updates can be done without a USB to serial adapter.  We have tested this GTOCP4 version here, of course, but I'd love to have some of you give it a try before I post it as the new  VCP4-P01-14.  

Thanks!

Howard

On 11/8/2019 10:03 AM, Daniel Marcus wrote:

Hi Mike
missed part of this conversation, so I am assuming you have already done
this but -just curious - have you tried a different GFCI circuit ( one
that is using a different GFCI protector)

I did not try the power supply on the other GFCI circuit in the observatory.

or measured the leakage current to ground?

I checked AC voltage to ground through a 1 meg resistor, and there is no potential on either DC output terminal or on the power supply case.

GFCIs are notorious for going bad. Could be the GFCI
is in the process of failing and is too sensitive?

Possible, but very unlikely. Both observatory GFCIs are one year old. Further, both have never tripped in that year of operation. The pier GFCI tripped ONLY when the Alinco DM-330V power supply was plugged in. Never before and never since.

--- Mike