I thought it was a unusual the fuse on 12 year old equipment would fail. I guess I was very lucky that the three 25-year old condensers I replaced had the original fuses. I can't recall the last time someone on this forum reported a situation like this. But then again I'm a homeowner with no formal HVAC training.

I can accept a fuse failing, but giving a customer no invoice and then charging his credit card two months after the fact made the repair questionable in my opinion.

OP, do you live in or near Katy, Tx?

Seems likely!

You left out the most important sentence

Compressor Hard Start Kit

• Single-phase units are equipped with a PSC compressor motor. This type of motor normally does not need a potential relay and start capacitor.

The manufacturer is basically saying the hard start kit may be required if the supply voltage is less than 230 V. But the service company does not measure the supply voltage and put it in their report as the justification for installing the hard start kit. We are not sure if their ammeter can accurately measure the LRA current at start up. If it could they would have sent you a photo of the meter reading.

File a warranty claim.

It's "assuming" because I didn't see the actual meter readout, so at the very least it's a valid hypothetical question that any HVAC should be able to answer. If you're a tech, or a tech on this thread cares to answer, given what the Lennox manual indicates as noted a couple times above, if a system's LRA is 15 amps above the LRA spec, and voltage is within specs, what do you advise the customer?

If your pay would go up if you sold a $600 part. (A conflict of interest you'd rather ignore.)

Sales Rep says: (buy this, buy that, buy, buy, buy - he's in sales what do you really expect him to say?)

The manufacturer: The system is designed and engineered to perform as it's listed from it's specific efficiency page. They then put a warranty of a usually 10 years maybe more on the parts of that machine to cover the life of those parts.

Now you think the manufacturer has intentionally left something out so they can get a costly warranty claim against a part of the machine that is the more expensive part?

With the large “boost” of capacitance from the Hard-Start Kit, compressor failure WILL occur after an extended time running without the motor-run capacitor, accompanied by the repeated “hammering” the motor takes from “high-boost” over-capacitance starts.

Meaning that if the system wasn't "engineered" to require a hard start, death of the so called part you're trying to protect is going to die anyway.

The clue is "over capacitance" starts. The kit was not sized properly to the specific compressor. There is more than one type of compressor and some models have / use different compressors depending on size (capacity) of the machine.

Some manufacture models protect the compressor if it detects a motor-run capacitor fail, which will prevent the compressor from trying to run in that state.

This is all upper level classified info that companies that sell these devices regularly do not want you to know. (The device they claim is protecting your compressor, is probably killing it one start at a time.)

The LRA reading is insignificant "ONLY IF"

• The compressor starts normally. Does not go into "off on over load" state. Compressor OL over load is a protective device that if the compressor does not start it will take the compressor winding out of circuit. (Typically less than 1 second upon engaging)
• The breaker to the compressor is not tripping / does not need resetting at any point. Continued tripping breaker? A problem that should be investigated.

The reason (my guess) why they use an LRA reading to suggest you need something is because they know it's a grey (gray) area in which to talk you into to buying something, for a problem (that appears to me) you don't have.

I know there's a problem here some where. Let's fix it. (fine if I am on the clock) not so much in a forum board. LOL.

A 1500 W electric space heater will provide about 5000 BTU. That is probably enough to keep the a 500 square foot space in the 45-50 degree range to keep pipes from freezing. It is hard to tell without knowing the insulation values and the lowest outdoor temperature.

Are you worried the main heater will run out of propane? If there is a power outage the electric heater will also fail.

Use a modern self-regulating heating cable such as Raychem Winterguard. The old Frost King style heating cables with a thermostat were notorious for burning out if not properly wrapped with continuous, intimate pipe contact. The modern semiconductor based cables self-regulate along their entire length and cannot overheat, they are worth the higher cost.

https://www.outdoorradiant.com/index.php?route=product/category&path=72