Rewiring the air conditioner control wiring in the furnace easily fixed the problem. The first short in Denver gave the technician a reading of 24 volts at the condensing unit contactor, but the contactor would not engage. Low voltage shorts in your air conditioning system are some of the most difficult failures to diagnose. Whoever had installed the furnace had not wired in the common control wire. If the voltage is zero across the secondary leads, the CPT is shorted and needs replaced. This website requires certain cookies to work and uses other cookies to You want to avoid resetting the breaker a number of times because you may actually blow the electrical dead short open, leaving an open feed somewhere within your walls. Visit our updated, Top 5 Fan Array Technology Advancements in 2020. The technician began by reading 24V at the contactor in the condenser, but the contactor would not engage again. Low H.T. When all of the control wiring is removed from the diagnostic, then the ac system can be tested by jumping the controls directly at the control board. This lead the technician to trace the missing  common control wire. Some shorts are direct shorts, which commonly causes a fuse in the furnace to open. If you cannot locate the problem quickly, you may want to call a licensed electrician to troubleshoot the job. The most logical first reaction is that the contactor coil is defective. By visiting this website, certain cookies have already been set, which you may delete and block. How do I test/detect where it is. Low voltage shorts in your air conditioning system are some of the most difficult failures to diagnose. Check all fixtures and splices for defects. When an experienced tech comes across this type of instance he or she learns not to trust what his meter is reading. When the thermostat was replaced and the control wiring was connected the entire system ran properly. This causes extra current to flow through the circuit, which causes the circuit breaker to trip or the fuse to blow. When the common leg of the control wiring was bypassed by connecting the common side of the contactor to ground the contactor engaged. (e.g. The best way to find the location is to disconnect the external secondary circuit from the CPT and take a voltage reading at the CPT's secondary. If the bulb glows bright there is a short so trace the voltage from the power transformer and look for a short--and don't forget the bias circuit. For Delta-Wye Contactor Troubleshooting refer to: Wye-Delta Contactor - Troubleshooting Guide - NGC. 1. GE Low Voltage Troubleshooting Tips Use this GE low voltage lighting troubleshooting guide to track down which parts of your vintage General Electric low voltage wiring system need replacing. data. Visit our updated, This website requires certain cookies to work and uses other cookies to help you have the best experience. The quick connectors which accompany most outdoor low voltage fixtures are designed such that moisture gets in the wire. block. Both shorts had similar readings caused by different reasons. Line. There are many potential problems in electric circuits, such as faulty wiring, broken insulation, circuit overload, as well as defective plugs, switches, cords, and receptacles. Weatherwise, Air Conditioning Denver : Troubleshooting a low voltage short. An output voltage significantly lower than the rated output for that winding indicates a turn-to-turn short in that secondary winding. To make this challenging diagnosis and repair easier, I take a step-by-step approach when dealing with a low-voltage issue in a residential unit. See the Vector Drive short-circuit inspection section below. There is a problem with the DC Bus. For a voltage lower than 2.0 V please check CAN_H and CAN_L conductors for continuity. Interested in participating in our Sponsored Content section? Now the problem with surge protection devices is that there are no real requirements or specifications for their design. Troubleshooting a solar (pv) system Below I will describe basic steps in troubleshooting a PV array. Take the Basic Circuit Troubleshooting (Basic Electricity) worksheet. (Contactor, Coil, Relay, Brake etc.) Twist a solid connection and use outdoor wire nuts. I find no control power and breaker on transformer is tripped. I have a low voltage short - keeps blowing the 3 amp fuse. voltage ; Low High tension. … help you have the best experience while on the site. By visiting this website, certain cookies have already been set, which you may delete and block. Alarm 123 SPINDLE DRIVE FAULT. Common issues are zero power and low voltage output. How do I find a low voltage short? Go to next step (Power supply good) The procedure here is first check all wiring. function openCommentPopup(){ Copyright ©2021. Some shorts are direct shorts, which commonly causes a fuse in the furnace to open. When a new contactor would not resolve the issue, further troubleshooting was needed. Problem: The fuse on my control board blows constantly. Answer: We have many customers ask how to find a low voltage short when the low voltage transformer is burning up or the fuse on the control board constantly blows? Some electrical dead shorts can be very difficult to find. Alarm 160 LOW INCOMING AC LINE VOLTAGE. The grids normally have zero or low DC voltage so I take my signal sample from the grids unless I … If the voltage reading does not match the stated input voltage, troubleshoot the voltage source before continuing with the transformer. Electro filters) Output valve red. The failure was in the furnace. This corroded connection now has a high resistance instead of a low … For a voltage higher than 4.0 V, please check for excessive voltage. If any wires are in contact with the chassis of the equipment, the fuse will blow. this website, certain cookies have already been set, which you may delete and this website. Place one of the multimeter leads on each input-voltage terminal and record the voltage. We all hate the grounded low-voltage wire that seems so hard to find. window.open("https://www.homestead.com/~site/Scripts_BlogElement/BlogElement.dll?cmd=CMDPostComment&handle=1757457589&popup=Y&entry=air-conditioning-denver-troubleshooting-a&partnerId=1&path=/Blog.html&domain=www.weatherwiseheat.com", "_blank", "left=100,top=100,height=500,width=600,location=no,directories=no,menubar=no,resizable=no,toolbar=no,titlebar=no,status=no"); If the control system in the furnace is not protected with a low voltage fuse, additional failures may occur to include damaging the transformer in the furnace. Usually, these types of transformers reduce 110 volts supply into a safer 12 volt to allow low-voltage lighting in landscapes or gardens outside homes. First thing we do on a repair is remove the connectors, strip the wire back 1 1/2 inches. To resolve the backfeed problem, the ac tech isolated the control wiring at the furnace by disconnecting the thermostat wiring at the control board in the furnace. Check CAN_H and CAN_L conductors for continuity and causes high current is usually connected to a battery or a.... Article describes how you can troubleshoot a solar system in Basic steps or troubleshooting low voltage shorts their! 5 Fan Array Technology Advancements in 2020 24V at the furnace to.. One side of the wires were shorted to ground the contactor in the insulation easily shorts the electrical supplying. Lead the technician to trace the missing common control wire similar readings caused by different reasons and how we and! 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