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Electrical Transformers


Purchasing Reconditioned Electrical Equipment

Debunking the myths about tested and refurbished equipment BY RISHI SUDAN, RS Electrical Supply Extending the lifecycle of capital equipment such as 15-kilovolt circuit breakers, switchgear, and transformers through testing and reconditioning saves time and money by cutting down on new equipment...

Grounding Transformers Explained

By R. W. Hurst, Editor Grounding transformers are used to provide a path to ground for unbalanced load current and for fault currents on systems where a suitable ground is otherwise not available. Grounding transformers are normally constructed with one of the two configurations: Zig-Zag (Zn) with...

Electrical Transformers

transformer repair

Radiator Fin(s) Leak Repair

Radiator fins are notorious for leaking at various locations. One of which is where the fins are attached (welded) to the horizontal bottom-run header. Measurements are taken so a weir box can be installed to cover the fin(s) that are leaking. It is preferred the weir box will cover above the leaking area about 6".
This 6” cover will allow for urethane (poured into weir box) to adhere to the drier part of the fin(s) to assist with the sealing process. After pour, the technician will mark the outside of the weir box at the location(s) where the original leak was. This incase further work may be required for a better seal. After the urethane is poured and let to cure (usually overnight) the job is inspected to determined seal effectiveness. In the event we still have some leakage; whether the following day or later, an additional procedure may be performed. If leaking, the weir box is fabricated out of 11ga galvanized sheet metal which is thick enough for completing a 1/16" NPT. The technician will decide where (usually where it's been marked) and how many 1/16" D&T’s (drill & taps) are required. Once additional d&t's are completed, injection valves installed, then a special 2-part sealant (must be approved from a dielectric and DGA standpoint) will be injected. The thought is: now that there is cured urethane above the original leak(s) and we have marked the weir box for injecting close to that spot, we have created a bridging barrier for our sealant to back up against (so as not to extrude out the top of the weir box).

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Power Transformers Health Check

Power transformers are static electric machines used to step-up or step-down voltage in electric power applications. The capital cost of a power transformer in the range of 100MVA can be $1M or more and by the time it is under operation, the price is increased. The average age of installed large...

Pennsylvania’s Yaw Bill

In a significant move for Pennsylvania’s energy sector, State Senator Gene Yaw has introduced a transformative piece of legislation aimed at modernizing the state's approach to power plant development and capacity management. The bill, which has been the subject of considerable discussion,...


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