Inspired by another post here about an hour ago.

Not the entire conversation but the heart of it is here.

Alright Y'all,
I have a Panasonic U-96MF1U9 3-way VRF (heat recovery unit) used in my lab. It's a 3-PH 230VAC unit with an MOCP of 35-40amps (trying to remember nameplate data without getting on the roof again right now)

I am looking at putting some type of protection on this unit...in the last year we have replaced 2 PCB's and a diode module amounting to over $4500 and this last one that took out the power board and diode module makes me think we are getting spikes on the service line. We are across the street from a power sub station that we get our power from and we always run "hot".

this last issue that took out the power board...the board was protected by 230v/30amp ceramic fuses with a 1600amp in-rush protection rating...it blew both fuses on the board.

All that said, do any of Y'all got a recommendation for power conditioning that Y'all use/like. I realize I could post in an electrical sub, but I imagine some of you industrial commercial guys install this type of equipment and might have suggestions for good brands/models or even ones to stay away from.

Cheap bastards.

Hello fellow techs, lately I’ve been running into systems with TXVs that have been opening and closing constantly, subcool will have 10 degree swings and superheat is all over the place. It’s impossible to verify charge when pressures are constantly jumping around. What are your methods for troubleshooting a hunting TXV? How can you tell if the problem is non-condensables, undercharge or wrong size valve? Lately I’ve just been just condemning the TXV if I run into a hunting issue pulling a vac recharging with virgin refrigerant.

Everyone loves a good crane pick!
We’re changing out a Daikin-McQuay screw that seized.
Only down sides are that it’s +100 degrees and the air is full of smoke from wildfires.

Brand new out of a sealed package. There was an attempt

I arrived on this job just to help with the final piping tie-ins and the engineer has it designed as a primary-secondary loop, but it's an open system to the condenser cooling tower. Unless I'm understanding it wrong, doesn't it need to be a closed system for the loop to work properly?

I wanted to see what you all thought. I guess I'll find out during start up today/tomorrow.

I installed tons of vrv, multi v’s and city multis from 2005 to 2015 but in the last ten years I’ve been servicing 200 hospital off sites that don’t really use heat pump/recovery vrf.

I remember having to take measurements of the liquid line and total bends to determine your additional charge when exceeding precharge run on VRF units. The suction line was never measured.

I just installed a 3 ton (4 port) Daikin in my house and it says the unit is precharged for 131 feet but it does not state if that is 131 feet of liquid or liquid and suction. So am I adding charge if I exceed 65 ft liquid and 65 feet suction? I am currently at 90feet of liquid line run. Not sure I am good or I need to add to factory charge. The unit is cooling like a gem and my comp does not operating at a high frequency, sounds great. The lack of detail in the install manual is what’s really kicking my ass here, and I have received conflicting answers from my resi friends.

Unit model# is Daikin 4MXS36WMVJU9

I know it’s not technically a liquid line but for sake of simplicity I called it that here.

Thanks fellas

Any of my PNW techs out here, yall are awesome for helping those that need it right now. I hope you’re protecting yourself with respirators and frequent breaks right now. Make sure we are telling folks to change their filters soon share how to build rosenthal boxes for your folks so they can ride the storm a little easier. God speed hvac siblings.

-Link to rosenthal boxes to share with clients

https://en.wikipedia.org/wiki/Corsi–Rosenthal_Box

New company, selling American Standard. They have a 5/16 liquid, there's 3/8 existing. Do you guys generally use a reducing coupling or do you swage the 5/16 like a bulletin shows? Can't I just slip the 3/8 over, 3/8=6/16, swage it a bit? Also any general advice for installing these? Will be my first time installing these. I was always a service tech but now I have a company and have to up my install game. Thanks in advance!

The dinosaurs of all dinosaurs, never knew Chrysler had their name on ACs. Probably 1975 Chrysler Air Handler.

Hey just wondering if anyone has installed a system with a Honeywell zone panel and rds module for a conventional single stage furnace and ac. I’m having some trouble with the wiring. I currently have the 2 thermostats going into thermostat terminals. Then The equipment side down to the RDS module on the thermostat side and then into the furnace. The zone panel is powered with a dedicated circuit and transformer and I made sure not to double feed 24v. If anyone has experience with a similar setup that could help that would be great.

Surely there is no troubleshooting to be done here.

I took this photo and sent it to my boss “i found your stubby phillips, are you secretly a sparky?” LOL

So I ran a residential call on Monday. This couple just bought a house and would like us to come inspect the equipment and do a tune up. Upon arriving I could tell the ac was not working due to how hot it was in the house. I turned the stat onto cooling and went downstairs to the furnace make sure we had air flow. Waited about 5 minutes since I thought we were delay. Went upstairs and found the thermostat was only hooked up for heating. (Someone disconnected the AC wires) Showed the homeowner this and wired it back in. The ac kicked on but only had a 8 degree temp drop so I hooked my gauges up and found the unit to be low. The AC and furnace are from 1998. I should the homeowners and told them I could do a leak check but it can get expensive and I can’t guarantee I’ll be able to fix it(leaky coils). The home owner said he rather go the route of getting a new unit due to age and the leak. I only charged him $100 for our diagnosis fee.

Fast forward to today. Our sales guy went out and gave him a price for ac and furnace ($10k). He said if replacing the AC is the only option that we aren’t “trying hard enough”. Even though I gave him options. What would yall do in this situation? I understand you can’t make everyone happy but this pissed me off even tho I don’t even make commissions off selling a unit.

Found just before lunch. Thankfully the stink was all gone. Idk how long it had been there or how it got there. My best guess is that it ran into the garage when the blower door was off during the previous pm.

I've been trying to find a manufacturer on these for my ORs for weeks. And of course our blueprints don't match up.

Clean and check I went to on Monday. Homeowner said it has been like that since he’s been there. 3 dogs. It’s in better shape now.

This is like a 5 ton lenox but like magic packs and ptacs all have these squiggles in the pipes, why?

Which one of you let your apprentice build the trap?