Temporary cable connection on gen-sets. Connecting at the gen-set breaker: Risky!

Wednesday, June 4th, 2014 and is filed under Commercial

Perhaps the most common location for connecting load banks to do testing is at the Gen-Set output breaker. Just loosen the lugs, remove the building load cabling, and attach your temporary cables directly to the breaker. Start the generator, close the breaker, and you’re ready for the test! Right? But wait, let’s consider the risks when choosing this method.

Connecting to the generator breaker usually requires disconnecting your building cabling. This creates risk to your loads should a power outage event occur. And especially in Life Safety or Mission Critical applications, choosing this kind of connection creates significant liability and risk to life and property. A generator breaker which has an additional set of lugs can be used to connect the temporary cable without disconnecting the building load. For this configuration, a load-shed feature on your load bank should be used to detect a power transfer to the building loads.

Another significant risk of using the gen-set breaker for connecting your load bank: lug maintenance and repair. Over time, lugs can wear out and require replacement, usually at the most inopportune time; during a load bank test! And when this happens, there’s down time and additional expense. Labor, parts, rentals, electricians, more time and more expense … not a good situation. There’s got to be a better way!   Read More

Wet Stacking and Load Bank Testing

Monday, June 2nd, 2014 and is filed under Load Banks

Most generator companies understand the negative impact of prolonged no-load generator operation and are aware of WET STACKING. This condition occurs when diesel engines operate at light loads and low temperatures for prolonged periods. Having worked in the generator industry for over 35 years, I have seen many cases of Wet Stacking, some severe. The photos I have shared are of an Emergency Standby Gen-Set here in Austin, Texas which ran for several weeks due to a main electrical buss failure. The customer had no choice but to run the system for an extended period of time under very light loads. As was the case for this customer, the solution of an extended load bank test usually restores an engine to its designed level of performance. However, leaving a system un-tested or under-tested until such visible conditions exist are risky. In fact, once a Building Engineer observes the oily sludge running down the side of his engine, it’s probably too late…the generator system performance is already compromised! Read More