“Cold Load Pickup” Can Prolong Your Outage
When your power is out, it is very frustrating, and you can’t wait for it to be restored. Line Crews do their best to restore power quickly, often in severe weather. What you may not realize is that consumers may be unwittingly prolonging the outage by having too many items drawing power once it is restored.
This is what is known as “Cold Load Pickup”. In this case, “cold” refers to the state of the power load, not the temperature of your location. We saw it happen in the Eagle Pass area outage during particularly cold weather the last week of December 2020. Line crews would close the circuit, and it would immediately trip again.
When large restoration procedures take place in cold weather, one of the issues the distribution system faces during the re-energizing process is known as ‘cold load’. Cold load is the amount of electricity customers’ homes demand as repair crews try to re-energize areas that have been off for extended periods of time. In some cases, this causes greater demand than the system is designed to take all at one time, and shortly after the power is restored, circuit breakers automatically trip to protect the system from overload, and the electricity goes off again.
The main cause of this problem is the large number of electric heaters and furnaces coming on at the same time, which places an unusually heavy load on the system. Consumers can help by turning off the breaker switch to their furnaces in their homes, if their power is out. The same applies to air conditioning systems in the hot summer months. Consider unplugging other large appliances, and electric space heaters, and gradually adding them back one at a time once power issues are resolved.
When the electricity is restored, you should leave the furnace off for about 30 minutes so our system can ‘settle out’ after restoration, then turn on the furnace and gently bring the temperature of the building up to a comfortable level. The outage you prevent may be your own!
This condition isn’t unique to Rio Grande. It is a common occurrence during temperature extremes - both hot and cold weather - due to the large power demand drawn by furnaces and air conditioning systems.