Parents are being asked not to bring their children to Temple Street Children's Hospital today (August 4), following a major issue with the power supply there.

A small number of patients have been transferred to Our Lady's Children's Hospital Crumlin as a precautionary measure and 20 surgeries and all elective x-rays, which were scheduled for today, have been postponed.

"All other current inpatients are stable and can be cared for within existing resources," the hospital said.

It explained that at 3am this morning, it experienced an eight-second interruption to its power supply, leading it to switch over to run off its own generator. This is standard practice in such events.

Following this, it was discovered that the transformer in the hospital's own sub-station had developed a fault and shut down. This means it must be replaced, which is expected to happen on August 6.

An additional generator is now on the way to the hospital and should be connected by this evening. This will ensure the supply of power until the new transformer is in place.

"Although we have UPS (Uninterruptable Power Supply) in key clinical areas, we made the decision early this morning to transfer our (five) most critical patients to OLCHC purely as a precautionary measure until the additional backup generator is installed.

When the additional generator is installed, we will resume our normal services in our Emergency Department (ED) and Outpatients Department and our planned elective surgeries," the hospital said.

Until then, the hospital is calling on parents not to bring their children to Temple Street. It is also calling on parents not to bring children with non-urgent complaints into the EDs of OLCHC and the National Children's Hospital in Tallaght.