Articles by John Tomczyk

The Professor: A Recap on Oil Traps

Functions, Dealing with Oil Reservoirs
By John Tomczyk
No Comments

The function of an oil reservoir, commonly known as an oil trap, is to prevent large oil slugs from forming. This is accomplished by trapping a small amount of oil in the reservoir or trap and gradually returning it to the compressor.


Read More

The Professor: Defining the Impact of Frosted Compressor Head

What Frost on a Compressor Head Is — and What it Isn’t
By John Tomczyk
No Comments

All frost means is the suction line or compressor is below freezing, and the moisture in the air has reached its dew point temperature and condensed. 


Read More

The Professor: Oil Pumps and Net Oil Pressure

Understanding the Differences is Key for Successful Servicing
By John Tomczyk
No Comments

Often, compressors in the refrigeration and air conditioning fields have forced oiling systems. Here is a look at some of those oil pumps.


Read More

The Professor: Don’t Forget About the Oil Check Valve

Dealing With Startup and System Problems
By John Tomczyk
No Comments

An overview of the oil check valve, which will only let oil pass from the compressor’s motor barrel to its crankcase.


Read More

The Professor: Troubleshooting Using Compressor Discharge Temp

Checking Over an Often Overlooked Aspect of Servicing
By John Tomczyk
One Comment

The compressor’s discharge line temperature is important because it is an indication of the amount of heat absorbed in the evaporator and suction line and any heat of compression generated by the compression process.


Read More

The Professor: Crankcase Heaters

Coping With Refrigerant Migration
By John Tomczyk
No Comments

Migration of refrigerant to the compressor’s crankcase during an off cycle is a serious problem, as significant compressor damage can occur if the problem is not remedied. 


Read More

The Professor: Understanding, Avoiding Transformer Burnouts

Solving Low-Voltage Power-Consuming Faults
By John Tomczyk
No Comments

This column will try to explain the voltages associated with the high or wild leg coming from the secondary of a Delta service transformer. 


Read More

The Professor: ‘Wye’ or ‘Star’ Configurations

A Look at Electrical Service Transformers
By John Tomczyk
No Comments

John Tomczyk discusses the Wye or Star configuration of the three-phase electrical service, which usually delivers four wires to the building.


Read More

The Professor: Low Ambient Controls Reduce Head Pressure

Control Is a Style of Head-Pressure Control Valve
By John Tomczyk
No Comments

When refrigeration systems are exposed to low-ambient conditions, the condensing pressure (head pressure) will fall. If the head pressure gets too low, the metering device will not have enough pressure drop across it to operate properly.


Read More

The Professor: TXV Dos and Don’ts

The Externally Equalized Thermostatic Expansion Valve
By John Tomczyk
No Comments

The thermostatic expansion valve (TXV or TEV) is a metering device located between the liquid line and the evaporator. 


Read More

Multimedia

Videos

Image Galleries

2014 Energy Efficiency Forum

Highlights from the 25th annual Energy Efficiency Forum in Washington, D.C.

Podcasts

NEWSMakers: Mark Satterfield

Mark Satterfield, founder and CEO of Gentle Rain Marketing Inc. and author of “The One Week Marketing Plan” talks about his book and the importance of HVAC blogging. Posted on Sept. 19.

More Podcasts

ACHRNEWS

NEWS 09-15-14 cover

2014 September 15

Check out the weekly edition of The NEWS today!

Table Of Contents Subscribe

Venting R-22

The NEWS reported that a man received prison time for venting R-22. Should EPA step up enforcement?
View Results Poll Archive

HVACR INDUSTRY STORE

plumbing-hvac.gif
2014 National Plumbing & HVAC Estimator

Every plumbing and HVAC estimator can use the cost estimates in this practical manual!

More Products

Clear Seas Research

 

Clear Seas ResearchWith access to over one million professionals and more than 60 industry-specific publications, Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.

DON'T MISS A THING

Magazine image
 
Register today for complete access to ACHRNews.com. Get full access to the latest features, Extra Edition, and more.

STAY CONNECTED

facebook icontwitter iconyoutube iconLinkedIn i con