Power Failure Accidental Causing Wireless Fence to Trigger

A reader had an unfortunate experience where a power failure lead to her dog getting a correction from a wireless system. The answer really gets to the root of why wired systems are so much better than wireless.

We have the petsafe wireless unit and have been pleased with it until this shocking due to power outages. We recently picked up another base unit and want to make sure that it’s okay to put together two base units rather than a transmitter to extend the range. Maybe they are the same, but I’m not sure.

Last night, my terrier was laying on my lap while my husband and I were watching TV. The power goes off and the terrier’s collar started beeping and shocked him before I got it off. Thank goodness we were home, but now I wonder how many times this may have happened. He’s outside most of the day, but we bring him in every evening. We looked at the literature and it’s not supposed to do this. Is it time for repair? I am assuming that the problem is the base unit.


ADMIN – Hi Shelia,

You can use base units and extenders interchangeably – they are the same unit.

You are correct, when the transmitter has a power failure and stops working it should not trigger the collar. We find these units generally unreliable. You should definitely get it checked – but it is also a problem inherent to wireless units.

The wireless systems basically all work by transmitting a signal that is detected by the collar. They have what we call a negative trigger. When the dog gets too far from the transmitter the signals get weaker and the correction starts. The problem they have is that lots of things make the signal weaker – such as the dog going behind a tree. In your case it seems like what happened is that there was a power failure and so the signal stopped going out which the collar thought meant the dog was escaping.

By contrast, wired systems work the opposite way. They have a positive trigger. The collar is used to getting no signal. Only when the dog gets too close to the dog fence, does it pick up the signal from the wire and trigger the correction. Because the only thing that can trigger the collar is actually getting close to the boundary wire – wired systems are much more reliable.

You may be able to sidestep the problem by putting the batteries in the back of the unit, so when there is a power failure it switches to battery backup.

1 Comment

  1. Jim Alexander says:

    I am a believer in the wireless Pet Safe Collar.. I have a question on the last statement above.

    “You may be able to sidestep this problem by putting batteries in the back of the unit. ” I have the IF 100 system (or S402-855) and I see no place to put batteries. Is this a separate purchase?

    ADMIN – Hi Jim. This is a response from 2010 and the systems and transmitters have changed quite a bit in that time. Most systems currently sold, including the system you have, do not have a battery backup like many of the older systems. If you are looking for a battery backup solution, I would recommend looking at a Universal Power Source. This is what many people with home computers or entertainment equipment use for their gear. This Power Source will usually allow for enough time to get your dog contained or to remove the collar so that the dog does not receive a correction in error. You can usually find these power sources at office supply shops or on Amazon.

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