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I have seen them repaired with solder while on a vacuumed pump.

I don't remember how I finally came up with the solution. My notes say to add a 500 ohm resistor in parallel with the load. It worked then and is still working today.

I can't open my notes here at work but I remember that the inputs on the VFDs were 1K impedance and the output needed a maximum of 500 ohms impedance. I believe I used a 1K resistor in parallel with...

I just looked it up. The 0-10 output of the i-Vu controller I used has a minimum impedance of 500 ohms. The input of the drive was higher so to get it to work I added a resistor. I can't look it up...

Your right, it was the output that needed the resistor to draw down to zero. I must have put the resistor at the controller. It has been years since they let me do controls.

Yes you can. The only limit is if you need a resistor on the inputs to make them go to zero. In that case I would daisy chain them and put the resistor at the end.

Post your resume on Linkedin. I had a head hunter call me. He found me there. He didn't have anything in my area. Find me there and I can forward you his account.

Linkedin has been sending me a few controls jobs for capital land in NY. The rest are from NYC.

It sounds like possibly the backup battery had died in the controller causing it to lose its program. The contractor had to download the program to the controller to fix that.

The best hint I...

The round magnet is probably a Ferrite toroid commonly used to prevent electromagnetic interference. There might be a strong radio source nearby. Reusing it shouldn't hurt anything.

OL means it is higher than the Megger can read. It sounds like capacitance interference. I would trust the initial reading and look for the short to ground elsewhere. If 2 fuses blew in a 3 phase...

When bare wire is below the wirenut it was not installed correctly and needs to be redone. If the wires are stripped the correct length there should never be exposed conductor.

Then they are not electricians. You can always tell non electricians because they tape their wirenuts.

I believe the romex got wet. When that happens the bare copper can get dark like that. Electricians know that bare is always a ground, no mater what color it is.

I programmed one in once. Basically you add a network input on all the programs you want to delay alarms for. You add a switch to break the alarm wire when it is in override. I put the time delay in...

A good electrician uses pig tails to prevent a loose connection on a device from bringing down the rest of the circuit.

From the website:
" Also we do remodeling of fire place, bars, basements, Tile work all kind and more."

I believe this is true if the parameters were copied to the keypad in the past. I might be thinking of the Z1000. It would be worth trying. There a command to copy the info back. If you need help let...

The big AAON units I have worked on had spring return dampers. Did you check to if the dampers are actually shutting? I have fixed dampers on AAONs where the pop rivets got loose the dampers bound up...

Any unit that works should work as a replacement. If the hard drive in the old unit died i believe it can be replaced and the OS reinstalled from the thumb drive that came with it.

The...

If you want to build your own controller you can try a Raspberry pi pico. It has both binary and analog inputs/outputs and is very inexpensive.

I was talking about the reflection from the light onto the evap cover.

Looks like a good photoshop. They added the light splash to the evap cover.

I had a PID randomly lock up. Rebooting the controller would temporary fix it. The fix was to appload a newer clipping and it never happened again.

Flickering DC = AC. It sounds like a short if the measurements were taken with the load side hooked up.

Where is the disconnect?

NEW is an acronym for "Never Ever Worked" I trust used parts more than new.

Electrician here. What is your actual voltage feeding the heaters? You could be on 208, or your 240 could be as low as 215.

There are 2 stage and variable rate gas burners. With custom control programing the space requirement could be met with one of these burners. Some form of reheat past the RTU with outside air...

You missed some options. Wood and coal. Since wood grows on trees it is the cheapest way to heat.

The GFCI looks at making sure the current in the hot leg matches the current in the neutral leg. If current is flowing from the hot leg to ground it trips. An isolation transformer will supply the...

It sounds like a Penn valve to keep the head pressure up on the compressor. It slows the chilled water return so the bundle doesn't get too cold.

I would set the min and max motor frequency in the drive. The PID then has to work within those settings.

I programmed for an older AAON unit with 2 stages of heat. This one had variable hot gas reheat. In dehum mode I used that to reheat with the compressors on full. If the supply temp got to low I...

It is not shutting off the compressor, it will still be running. It just won't be doing any or as much work ( I didn't read the specs) depending how it is set up.

Jet fuel and most rocket fuel is just highly refined kerosene. The contaminants they remove must be worth a lot. I'm sure someone will find another way to make them as the price goes up.

After a quick search I found https://www.perle.com/lp/ethernet-modem.shtml I am not sure this will fit your application but there may be more out there. It might be cheaper than a whole new system.

I believe you have it sorted. A trick I use is to set the color to something not used like purple, then I let the expression change it to what I want. If it changes to normal but not alarm then the...

It looks like they are calling the "common" a ground bu it doesn't show the common being bonded. Does that happen in the board? It also shows the gnd/common being daisy chained between boards. That...

I have had experience with a system that the shield was not landed on the controllers. Landing the shield helped a lot. If the building is that small why not just run new cable? If the existing cable...

There is a replacement smoke kit for british cars, so maybe someone will make one for HVAC.

You can use it with one pressure switch with one set of contacts. On the first hand drawn schematic you need to move the jumper from 1 and 4 to 1 and 5. This enables power to the compressor control...

If I wanted to do that in i-Vu/ALC I would put the overrides in the graphics with a general boolean that could disable overrides in the properties section. I would also have to set any restricted...

You may want to click the black triangle and ask to have this post moved to controls.

Are you using 2 different pressure units on purpose? Even if the pressures are all mbar they are still high. Your building pressure monitors may need to be calibrated. Wind at night might also be...

I am not familiar with the board but have you tried a power cycle of the controller. Leave the power off for at least 30 seconds.

I have to assume that the MSVs are set to network visible or you would never even see them. You may have to see the program to know what each number means.

I have seen MSV's words in i-Vu from a...

You can get a pressure switch with a low water cutoff to prevent that from happening. It is a pain after a long power failure because it has to be be held on manually to get the pressure back up.

You can connect directly to the board using the Rnet terminals and a USB dongle with a laptop running Microsoft Windows. I forgot what the buss is but I can look it up at home as I made my own. You...

I am using ((G - D)/E) + D

D = output
G = input
E = Amount of smoothing, 1 is none, 10 is max.

It then goes through a ramp set at .05 increase/decrease every 30 seconds.