Trane air handler troubleshooting Guide An air handler has many electrical and mechanical components that, without preventative maintenance, can degrade over time and reduce theIf you notice reduced or no air flow throughout your home, you will want to check your air handler unit’s air filter, evaporator coil, and blower motor for potential problems. Dirty or clogged air filters In order for your air handler to function properly, ensure that nothing obstructs the air flowing through your air handler unit. most common obstruction is a dirty air filter. your air filter regularly will not only improve the overall quality of your home’s air, but also prevent more costly repairs later on. new digital programmable thermostats display air filter change reminders making it easier than ever to ensure consistent system maintenance. Recommended Action: Examine the air filter in each of your system’s components. If the filters looks dirty, clean

or replace the filters as recommended in your use and care guide. problem persists, contact your local Trane Comfort Specialist Dirty or clogged evaporator coil Another common issue Trane Comfort Specialists encounter is dirty orThis happens when the system runs with noWithout an air filter, components inside the air handler become clogged with dust and debris. This can cause evaporator coils to freeze, which reduces the unit’s cooling capacity, and in some cases can force liquid refrigerant to return to the compressor. Recommended Action: Check for signs of water below unit and cold exterior surface of indoor coil enclosure. your local Trane Comfort Specialist. In the meantime, try turning your thermostat off for 1 to 3 hours to see if it will defrost. Failure to use or replace an air filter can also cause the blowerExcessive dust in the system makes the motor work harder, creating excess heat. As dust continues to build up, it can

eventually cause the motor to burn out and require a replacement. : If your blower motor fails contact a Trane Comfort Specialist. Failure of the blow motor will require professional service. Chilled-water pump does not slow down sufficiently as system load decreases air-ground control radio station Air-Ground Engagement System - Air Defense Air-ground Radiotelephone Automated Service Air-Heating & Cooling Coils Air-Installation Compatible Use ZoneAll equipment manufactured by Seller includes a limited warranty against manufacturing defects in materials for a period of one (1) year after date of initial operation or eighteen (18) months after date of shipment, whichever date occurs first. Should such a defect occur within the specified warranty period, and it is clearly shown that such defect was not caused in whole or in part by lack of maintenance, misuse or abuse of Purchaser in handling, operating or maintaining the equipment, installation of equipment by anyone other than Seller, failure to exercise due care in the protection of equipment during periods of idleness or storage

, or for any other reason not directly related to manufacture, then Seller will, at its option, repair or replace such defective parts F.O.B. Seller’s factory. All freight charges shall be borne by the Purchaser. In addition, the air handler’s panel casing and structural base shall include an extend forty (40) year warranty against structural failure due to corrosion under normal use. Unit casing leakage deficiencies found to be correlated to degradation of the casing structure and panel integrity shall also be covered through the full term of the extended forty (40) year warranty. four ton ac unit costStructural failure and/or casing leakage deficiencies found to be resultant of improper operation, care, or maintenance shall not be covered by the terms of this warranty. repair ac window unitAir Enterprises reserves the right to provide either replacement parts or provide materials for repair at the jobsite at Air Enterprises’ sole discretion. ac units for rv

The warranty covers material only. All repair labor is provided by others without recourse against or right of contribution from Seller. Seller reserves the right to inspect all allegedly defective materials and/or equipment. Seller will not be responsible for any design defects or other performance deficiencies contained in plans and specifications provided by the Purchaser or third parties. Only the Purchaser, and other entities listed by Seller on the face of this Warranty, shall have rights under this Warranty. All components items not manufactured by Seller included in the air handler are subject only to the terms and conditions of the original manufacturer’s warranty, if any. Seller shall have no warranty obligation for component items. For projects where Seller has installed the products, Seller warrants its workmanship and labor, for a period not to exceed one year from the date of Seller’s substantial completion of its installation. The date of substantial completion shall be as determined by Seller in its sole discretion.

Any damage caused by others or resulting from improper maintenance, abuse or neglect is excluded. SELLER SPECIFICALLY MAKES NO OTHER WARRANTY AND SELLER EXPRESSLY DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTIES, MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE. Seller neither assumes, nor authorizes any person to assume for it, any warranty not specifically provided herein. Seller shall not be liable for any incidental, consequential or special damages.Here are basic guidelines revealing how to troubleshoot variable frequency drives and get them up and running fast. The trick to troubleshooting variable frequency drives (VFDs) is to fix the problem and not the symptoms. When a fuse blows, is this the problem or a symptom of the problem? Of course we know it's only a symptom; something is causing the fuse to blow. We can replace all the fuses we want, but the problem will still exists. This same idea holds true for fixing drive problems. The first and most important rule for troubleshooting VFDs is DO NOT TROUBLESHOOT THE VFD!!

Troubleshoot the VFD application instead. So what is the VFD application? It's everything from the incoming power to the load itself. Fig. 1 shows the individual subsets of the overall VFD application. Like a car, a VFD will not operate properly with poor quality fuel. The incoming line power must be stable and adequate. Characteristics such as undervoltages, overvoltages, surges, etc. are usually the result of poor power quality. The VFD controller panel is the heart of the application. The VFD panel takes in a fixed voltage and frequency and gives out a variable voltage and frequency to the motor. In doing so, drive gives off heat. The bigger the drive, the greater the heat. Without proper cooling a drive will shut down on overtemperature. Overtemperature and overcurrent go hand-in-hand. Sometimes the faults will even interchange. An overcurrent fault could be the result of overtemperature. A clean well-ventilated drive always seems to work better and last longer. A couple of the best troubleshooting tools are a brush and vacuum cleaner.

In a VFD application, the motor reacts to the varying voltage and frequency from the drive and develops torque for the load. In doing so it draws current from the VFD. If the demands of the load are too great, the motor starts to draw excessive currents from the VFD. Eventually the current demands become too large for the VFD to handle, so it trips out on an overcurrent fault. Overcurrent faults are the most common faults that will shut down a drive. There are at least 20 to 30 causes of over-current faults. Finding the actual cause of the fault in question is the challenge. When dealing with these type of faults, always look at the dynamics of the motor and the load. The load is the reason for the application. Without a load there is no need for the drive and motor. Troubleshooting drives always begins with a clear understanding of the load. This simple concept can save you much time in your troubleshooting. Expert troubleshooters always have a well defined approach to troubleshooting.

This is not a set of troubleshooting instructions (which varies from equipment to equipment) but a way of thinking. The thinking process can be refined to the application of "SMARTS." SMARTS is a system that will help keep your thinking straight when troubleshooting. Safety is always your first concern. There are three questions you should always ask yourself before you do anything. 1. Is what I am about to do safe for me? 2. Is what I am about to do safe for those people around me? 3. Is what I am about to do safe for the equipment? These simple questions can help in preventing a deadly accident. Manuals are required to troubleshoot today's equipment. Microprocessor-based controls have smart displays and powerful diagnostics. However, these wonderful capabilities are useless to us if we don't have the manual to interpret the information being provided. Applications are what we troubleshoot - not individual pieces of equipment. A drive shutdown is usually the result of external conditions.

The last item to troubleshoot should be the drive control panel. Readings from the drive display panel indicate the cause of a shutdown. With the fault information in hand, a review of the manual will give you probable causes for the fault. A log of past faults is helpful in tracking recurring problems that have yet to be fixed. Other readings, such as line voltage and motor currents, give you an indication as to the overall health of the application. Recording readings over the life of the equipment is an excellent method of preventive maintenance. Don't forget temperature readings; a rise in heatsink temperature is a strong indication of future problems. Talking and communicating with machine operators or users of the equipment is one of your best troubleshooting tools. You should ask questions like when and what else was going on when the application failed can save you many hours of troubleshooting. Not all of your talking will be with people. Sometimes a review of the log of past events in the building automation system is all you need to solve the problem.

Simple solutions are usually all it takes to put a system back into operation. The vast majority of problems seen by the author over the last 20 years have been simple in nature. Some simple problems have been made complicated by over-reactive troubleshooting methods, thereby becoming very difficult. Always investigate the protective interlocks and safety relays first. Why bring in an expert to reset peripheral devices such as a smoke 'stat or freeze 'stat in a duct. Remember a drive needs two signals to operate: a start command and a speed-reference signal. Symptomatic troubleshooting is how experts focus in on core problems quickly and accurately. Look at it this way. If the receptacle in your office was not working right now, would you drive down to the main substation in the city to check the incoming feeders? Of course not, it wouldn't be practical. But think, how were you able to make the decision not to make the trip? You probably saw other lights on and knew in a split second that power was available to your part of the city.

This split second decision saved you a 3-hr trip. As you observe symptoms, ask yourself what could cause this symptom. Some symptoms can have multiple causes, but by negating or throwing out the ones we know not to be the problem, we can determine the true problem with greater speed and accuracy. Variable frequency drive problems will fall under one of three classifications as shown in Fig. 2. This chart will help in troubleshooting a drive application. Note we are troubleshooting the application and not the drive. A recent troubleshooting experience is a good example of how easy it is to be misled in separating symptoms from real problems. This customer has numerous large 125-hp VFD units mounted in roof top air-handling units that are used to supply conditioned air to a large manufacturing facility. Having provided start-up services for the installation, we were asked to assist in troubleshooting a problem the customer was experiencing. One of the 125-hp units was making strange sounds and acting unstable.

It was as if the unit was hunting all the time and experiencing many current surges. The customer was sure that the drive was misfiring somehow, creating very high current surges. In fact, the door-mounted current meter would swing from a normal 130A peak up to 180A and then swing down to 90A or so. The problem seemed so serious that the customer was ready to take the unit out of service and run it in its bypass mode. As we walked into the penthouse, we heard the sound coming from the unit. Our first reaction was to get this "troubled" unit shutdown in a hurry. As we were getting ready to shut down the unit, we noticed the volt and frequency meters on the door were locked-in and stable. At 50-Hz operation, the unit was operating at around 385V. The volt/hertz ratio was right on the money. We immediately realized that there was nothing wrong with this drive unit. We then explained to the operating personnel what a constant volt-hertz ratio is and how the drive was obviously reacting to a dramatic swing in load demand.

The real question was how a fan could show such swing. Tracing out the duct work and taking sample static pressure, we obtained readings that got us. to the real problem. An internal damper that was blocked open when the drive was installed had come free. It would drop down, closing off air flow. This damper action caused unloading of the fan motor. Eventually the static pressure would get high enough to blow the damper open, allowing the fan to load down. It was like a leaf blowing in the wind in the middle of the duct. The drive was doing its job, responding to the load changes to the fan motor. Once the damper was blocked open again the drive settled right down and operated correctly. In retrospect, the troubleshooting process began as soon as we looked at the door meters. We asked how a drive could hunt when the volt/hertz ratio was stable. What would cause current shifts like this, especially on a fan motor? While this was the fastest troubleshooting we had ever done (less than 2 min), it was the most unusual example of how a drive can be affected by the load.