Are you doing a first-time installation of a new commercial compressor?
If so, you should know about one of the most serious issues that can damage your compressor.
When performing any new installation, it’s crucial to have a checklist you can refer to, in order to make sure all is in proper order before you activate your equipment for the first time. However, it’s easy to overlook this one matter even when you’re following directions from the OEM service manual.
The problem is this: Accidentally or maybe on purpose, operating your compressor in reverse.
Reverse operation has the potential to destroy many different makes and models of compressors, not just the Paragon 06T. However, we’ve heard horror stories from customers and suppliers alike about this very issue.
Operating Your Compressor in Reverse May Leave You in Need of a Replacement
In contrast to heat pumps, commercial HVAC compressors are usually designed to rotate in only one direction. The stresses of reverse operation can cause significant damage to your Paragon 06T compressor after only a short time. The most common problems include:
Mechanical Damage
Mechanical damage will be nearly immediate when most compressors are operated in reverse. The valves are particularly vulnerable and will often need to be replaced. The extent of the damage depends on how long the system operated in reverse, but a full maintenance check should be performed.
Lubrication Issues
Lubrication systems generally only operate in one direction and may provide no support at all when the operational direction is reversed. That amplifies mechanical damage. In some cases, your lubrication system will be at risk of developing leaks. Proper lubrication levels should be verified before you return the system to normal use.
Inefficiency
In the event that the compressor doesn’t stop working right away, it will still perform at only a small fraction of its peak efficiency. You can expect poor cooling performance and increased energy consumption. In “mission critical” applications, cooling might not be high enough to meet safety standards.
Pressure imbalance, electrical stress, and much more are possible when you are operating a compressor in reverse. It might be the “best case scenario” when protection systems, such as pressure switches, kick on to prevent lasting damage. Luckily, a Paragon 06T compressor makes it easy to avoid the whole dilemma.
Ensuring the Correct Direction of Rotation for a Paragon 06T Compressor from Carrier
To ensure your compressor won’t operate in reverse, it’s crucial to verify the direction of rotation before you start it up. However, this can’t be done simply with a visual inspection. There are different approaches to verify rotation depending on your compressor. Here’s what works for the Paragon 06T compressor from Carrier:
1. Monitor the discharge gauge on the high-pressure connection port on the compressor’s body. While you keep an eye on it, “bump” the compressor – that is, turn the power on for about half of a second. Remember that a “bump” should usually be no longer than one second.
2. If the discharge pressure rises, then the direction of rotation is correct.
3. If the discharge pressure falls, then the compressor is suffering reverse rotation. The phase sequence should be reversed to compensate. You can change the phase sequence by switching any two leads within a compressor’s motor – unless a variable speed drive is in use. If so, proceed to the next step.
4. If a variable speed drive is in use, checking compressor rotation is a little more complicated. Return to Step 1 and check the rotation both through the inverter and through the inverter bypass. When you bump the inverter, bear in mind it can take up to five seconds for any significant rotation to happen.
5. Note that the phase sequence entering the variable speed drive might differ from the sequence leaving it.
6. If you notice incorrect compressor rotation with a variable speed drive, the solution depends on the exact readings. When the rotation is wrong both through the inverter and in bypass mode, any pair of leads should be switched at the compressor. If inaccurate readings are found only on one or the other mode, simply switch any two leads that leave the device causing the reverse rotation.
7. After wiring changes, verify the direction of rotation through both the inverter and bypass mode.
Replace Your Paragon 06T Compressor the Right Way
If you’re dealing with compressor damage, the most important step you can take is the next one. Reverse operation can quickly damage a commercial HVAC compressor beyond repair, but you can get back in working order fast by getting a remanufactured commercial compressor.
A remanufactured commercial compressor uses your compressor core (which is usually undamaged) as the basis of a re-engineered system where all necessary replacements are made and all functions are verified. It can cut thousands of dollars and weeks off your timeline for a new Paragon 06T compressor.
