Shaft voltage is a phenomenon that commonly occurs in electric motors powered by variable frequency drives. The rapidly-switching voltage pulses of VFDs induce high voltages in shafts and bearings that may overcome insulating properties of bearing grease, and the resul...

Accurate measurement of temperature, pressure, level, humidity and flow are essential to equipment and systems operation. Inaccurate instrument readings can have a cascade affect on HVAC systems, particularly large ones, and energy efficiency can suffer greatly when in...

PJM Mechanical Contractors, Inc. recently completed the installation of a large make-up air system as part of the renovation of a Central New Jersey technical school’s culinary arts lab. The project was on a rigid schedule to accommodate facility needs while the school...

When an electric motor fails, replacement might not always be necessary. With some skilled troubleshooting, motors can often be repaired, sparing owners the sometimes-great expense of replacing it.  Even if a failed motor is not repairable and requires replacement, it...

Plumbing as we know it today - potable water delivery, waste removal, and heating and cooling - is unquestionably one of modern civilization’s greatest achievements.

Rudimentary plumbing has been discovered as far back as 2700 BC, where earthen pipes reinforced wi...

The sewer system in a commercial building might be out of sight, but it certainly should not be out of mind. Maintenance of a sewer system protects commercial properties by preventing and correcting clogs, blockages, corrosion, cracked or collapsed pipes, and tree root...

A food and beverage company reached out to PJM with a pressing problem on a lab renovation project. Various equipment that had been ordered for several laboratories on the premises called for specific exhaust systems that needed to be installed before the new equipment...

One of the most important aspects of our business is our commitment to providing exceptional service to our customers. Good customer service – meeting or exceeding a client’s needs – is the key to any successful business relationship.

So, what is it about PJM’s customer...

Installation of laboratory gas systems generally requires three important considerations. 

1. Documents must be reviewed in detail to ensure that shutoff valves to isolate labs and other areas are included.  Oftentimes, these basic details are missing from drawings.  A...

Welding, cutting and brazing exposes workers and others to hazardous metal fumes and gas byproducts. In the short term, exposure to these fumes and gases can cause eye, nose and throat irritation, dizziness and nausea. Prolonged exposure can lead to lung damage, variou...