Articles by Joe Marchese

Ice Breaker: Testing Thermistors

Thermistors are one type of temperature sensor used on electronic control systems. Technicians servicing these control systems need to be able to test the operation and accuracy of these sensors. A defective thermistor can easily cause a controller to not operate correctly.
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Ice Breaker: Talking Oil Separators

An oil separator is an accessory used on some larger refrigeration systems to help limit the amount of oil in circulation. It is typically used on low temperature applications where the refrigerant’s mass flow rate is low. But it could be used on any system.
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Ice Breaker: First Steps of Service Calls

Troubleshooting a refrigeration system is all about gathering information and using that information to determine the cause of a problem. Technicians are always measuring voltages, amperages, pressures, and various temperatures to help them find a problem. Besides these important measurements, there are other pieces of information that can assist a technician.
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Ice Breaker: Starting a Stuck Recip Compressor

One of the common problems found while troubleshooting reciprocating compressors is that they simply fail to start. This could be the result of many different causes, both electrical and mechanical. One common mechanical cause is a stuck piston. Mechanically the piston cannot overcome an internal resistance to move.
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Ice Breaker: Troubleshooting Potential Relays

Many low and medium temperature single-phase compressors require some type of external relay to assist in the starting of its motor. The purpose of this relay is to remove the motor’s start winding, start capacitor, or both, from the circuit once the motor is running.
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Ice Breaker: Evaporator Superheat Explained

In a properly operating system, the refrigerant will be in a superheated state from the last section of the evaporator to the first section of the condenser. Technicians can measure the superheat condition anywhere along this path. One common location is at the outlet of the evaporator.
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Ice Breaker: Ask Why the Failure Happened

A service technician should not only fix the problem but also, to the best of his ability, ensure the system operates reliably. This means once a technician identifies the system problem, he should try to discover why the failure occurred and what can be done to prevent it from happening again.
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Ice Breaker: Reading Ladder Diagrams

Being able to efficiently interpret ladder (line) diagrams is an important part of electrically troubleshooting many HVACR systems. These diagrams are drawn in such a format that it is quite easy to understand the electrical configuration of the system.
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Ice Breaker: How Automatic Expansion Valves Work

The automatic expansion valve (AXV) is similar in construction and appearance to the commonly used thermostatic expansion valve (TXV). However, the metering devices operate much differently.
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Ice Breaker: Replacing Cap Tubes

A popular metering device used on many fractional horsepower refrigeration systems is the cap tube. But one field problem encountered with this type of metering device is that it can become plugged with system debris, causing a restriction.
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Scenes from the 2014 World Energy Engineering Congress in Washington, D.C.

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NEWSMakers: Cynthia Hutson

Cynthia Hutson, chairperson of ACCA of Central Ohio, talks about the organization’s Heat the Town events, the importance of carbon monoxide checks, and what is coming up for ACCA. Posted on Nov. 21.

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2014 November 24

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R-22 SUPPLIES

Now that EPA has finalized its R-22 phaseout plan, with a large drop in 2015, do you think there will be an adequate supply next year?
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2015 National Plumbing & HVAC Estimator

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