Surge Guard Model 34560

[Greg The Hammer]

I have a question about the above mentioned Surge Guard.  There is a cautionary prohibition to mounting top up, parallel to the ground. Can anyone explain the purpose behind this issue?  Mine was mounted to the floor, in the prohibited manner, and think I ought to change the mounting, but I?m curious technically why it?s an issue. There are no cooling ports being blocked, so that?s not it.

 

[Gary RV_Wizard]

At a guess, they don't want to risk water pooling around the wire exit ports at either end. All the permitted positions would channel water & dust away from the face of the unit. Face up on the floor would not.

You could also put a clear plastic shield over it, but I'd leave sides open for heat dissipation.

 

[Greg The Hammer]

Your point about moisture is well taken.  However, no mention of moisture is made since this unit is designed to be mounted in the coach interior, which should be dry, as opposed to a portable outdoor unit. Mine is located well on the interior, behind a panel in the basement. There should be no water present, bedsides the dreaded 100 year flood.  I?m thinking that it?s in relationship to the electronics, relays, etc. If the only purpose of mounting position restrictions is water penetration, then a horizontal mount such as mine should not be an issue. I?ll be calling their tech support tomorrow for background information, and I?ll post the answers. Thanks, Gary. 

 

[Harry B]

Just another guess, however I am thinking that it might leave the contactor hanging upside down which would reduce contact pressure. Other than what Gary mentioned, I can't think of another reason not to mount it face up.

 

[HappyWanderer]

The instructions for my portable unit are the same - I think they simply didn't change the text for the hard-wired units.

 

[Greg The Hammer]

Permanent units get mounted in the interior. Portable units just hang on the power pedestal. The portable unit includes a warning not to mount face up?  That seems odd to me.

 

[Greg The Hammer]

An issue with the main relay position sounds plausible. To my knowledge, little electrons don?t care about gravity. If it had a mercury contactor, I could see orientation issues, but I don?t think they?ve been used in decades. I hope to speak to an engineer, and not just someone who advises to ?read the instructions?. We all know that real men don?t read instructions. LOL

 

[HappyWanderer]

Permanent units get mounted in the interior. Portable units just hang on the power pedestal. The portable unit includes a warning not to mount face up?  That seems odd to me.

They don?t have to hang. When using a 50-amp extension cord, I generally put the surge guard on the ground under the motorhome, to keep it out of the weather. While in storage, the unit stays in a compartment.

 

[Gary RV_Wizard]

I think you are trying to read too much into it.  Engineers are naturally cautious - they don't like the notion of things sitting on the face of their beloved creations.

And as someone noted, the people who produce the manuals and install instructions borrow from other previous or similar documents to save time & effort, so often there are artifacts of this ad hoc sharing.

 

[Greg The Hammer]

Talked to Steve at TRC, the manufacturer of the Surge Guard.  They don?t want it mounted on its back parallel to gravity for the simple reason that if the relay failed mechanically, such as broken relay spring, it would fail closed, with no obvious indication of failure, and would provide no further protection. 
In addition, these units loose their calibration over time. It is calibrated to open on high voltage of 132 VAC -/+ 3%, bringing it pretty close to the 126 VAC I typically see on each leg.
This unit also looks at neutral to ground, which should be zero, but in reality, can be a couple volts. If that exceeds 3 volts it will open. This should protect from a ?hot skin? condition in the coach, such as I have experienced on a couple occasions.  These two instances of hot skin were when there was no grounding at the power source. It seems this unit would check for a good ground, but apparently it doesn?t.  But in each case, I was using an adapter to use a 120 volt source as 240 wasn?t available. So, other than rechecking my ground bonding and internal coach terminal connections
The unit is sealed, and can?t be opened up and serviced. It is calibrated during manufacture, and can?t be re-calibrated after manufacturing.

 

[John From Detroit]

I agree with the overcautious engineer comment. but then I studied engineering and.. You guessed it. I tend to be over cautious.

Mine is on it's side as I recall. Not "Top up" and it has tripped on "open ground" one time so far.

I like the time delay.. The time delay is kind of important.

Now I have not looked closely enough to mine to see if it's sealed or not. but I know the portable it replaced could be opened.