Installing the Vetralis monitor

Pull the disconnect beside the condenser. If the property has a breaker for the condenser, switch that off too. Then check with a tester at the disconnect terminals before your hands go anywhere near them.

Find both service ports. Confirm which line is which using the table above — bigger and insulated is vapor, smaller and bare is liquid. Then put a piece of tape on each and write on it. Ten seconds now, and you cannot mix them up later with cold hands and a dark yard.

While you are there, photograph the equipment nameplate. Make, model, serial and refrigerant type all go into the app at the end.

The magnet in the base does the whole job — nothing to drill, nothing to screw. Pick a flat steel panel on the condenser cabinet, wipe it clean and dry, and set the unit down squarely. It holds through wind, rain and mowing, and it comes off with a firm pull when the equipment is next serviced.

• Level, and square to the cabinet edge. A crooked unit is the first thing anyone notices.
• Beside the manufacturer's labels, never over them. Covering a data plate creates a warranty argument you do not want to have.
• Not on the fan deck, and not where it blocks the coil face.
• Somewhere you can still read the three windows standing up.

Screw the antenna onto the gold connector, finger-tight only — no wrench. Point it upward and keep it clear of the cabinet sheet metal. Never power the unit up with this port empty.

Remove the service port cap. The tee threads onto the port, the sensor goes on the branch, and the through-path stays available so gauges still fit for normal service. One tee per line, per the marking you made in step 2.

• Hold the valve body with a second wrench. Never let torque reach the line.
• Torque to the flare-fitting specification. Over-tight cracks a flare; hand-tight weeps. Neither shows up until next summer.
• Clean flare faces and clean threads. No tape and no sealant on a flare joint.

Both sensors are the same part and both are marked. Liquid side goes on the small bare line. Vapor side goes on the large insulated line. The seal is the flare face, so there is no O-ring to fit and nothing to dope.

Two tees, two sensors, four joints. Check all four with a detector or bubbles, and document it. This step decides whether the charge is still there in two years, and it is the one nobody can verify for you afterwards.

Each probe is marked for its line. Peel back just enough insulation to expose clean, dry copper about a foot downstream of the service port, lay the metal tip flat against the pipe, and hold it there with the first insulation patch. Put the second patch over the first.

• Metal on metal. The tip must touch copper — not foam, not tape, not air. Contact is the entire measurement.
• Two patches per probe. The second keeps outdoor air off the sensing point, which is what stops the reading drifting with the weather.
• Same line as its matching pressure sensor. Liquid probe on the liquid line, vapor probe on the suction line.

The supply takes 100–240 VAC and puts out 5 VDC. Its two bare AC leads land on the line side of the contactor — the same node as the load side of the disconnect. That way the monitor is powered whenever the disconnect is in, and dead the moment it is pulled.

Dress the AC leads away from the contactor's moving parts, keep the low-voltage lead out of the panel where you can, and close the panel properly.

One plug goes into the monitor's splitter port. Five labelled branches come out, and each has exactly one place to go:

• Power → the power supply
• Vapor pressure → the sensor on the large insulated line
• Liquid pressure → the sensor on the small bare line
• Vapor temperature → the probe on the large insulated line
• Liquid temperature → the probe on the small bare line

Line up the keyway before you turn anything, push the connector fully home, then hand-tighten the collar. It should not need force in either direction. The pin map above is for diagnosis later — in the field, go by the printed labels.

This is five minutes, and it is the difference between a product and a prototype.

• Every run secured. No cable touching the ground, no loops hanging off the cabinet face.
• Route the antenna lead along a cabinet edge, not across a panel.
• Leave a drip loop before each sensor so water runs off the cable rather than into it.
• Zip ties trimmed flush. No tails.
• Nothing routed across the coil face, the fan, or a service panel you will need to open again.

Push the disconnect back in. The left window lights immediately. The middle one starts blinking within a few seconds, and what it blinks tells you how far the unit has got.

This is the step that decides whether anybody has to come back. Do all of it standing at the condenser.

• Register the unit to the property — scan the QR code on the side label, or type the serial.
• Enter the equipment details you photographed in step 2.
• Run the system in cooling for ten minutes, then open the live view on your phone.
• Confirm all four channels are reading, and that the numbers are plausible — see below.
• Confirm the pressures are not the wrong way round. Liquid should read far higher than vapor.
• Send yourself a test alert and confirm it arrives.

Clear the base of the unit, take the packaging away with you, wipe the enclosure face, and take the photographs listed further down this page. Then show the owner the live data on their own system — two minutes on that is worth more than anything written here.