Can a - Little Gray Box - (water heater timer) be considered a disconnect?

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clarice

Member
This heater is in an outdoor shed and it is attached to a solar water heating system. The panel and breaker are out of sight. There is a manual override on the timer, but it does have the tabs that click it off and on so.....even when placed manually in "off" the timer tabs could click back on....I'm thinking I should use installed a separate disconnect. What is the view of our esteemed council?:confused:
 
cadpoint

cadpoint

Senior Member
Location
Durham, NC
With the mechanical time clock your only disabling the current flow or protential current to the the tank, the timer is still running, (you can even hear it) and can still trip as per the cycle setting.

You need to install a disconnect with-in site of the tank or put a locking tab on the circuit in the panel that serving the circuit, as pervious said!

Something like this HERE Note the lockable tabs on some!
 
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rich000

Senior Member
Doesn't the box have a manual on/off switch?

Just because the timer is still running has nothing to do with sending power downstream to the water heater.

Now if you turn it off and the timer still runs and then turns it back on, then that would be an issue to consider.

I would think it would be the same as a fancy controller for a pump with the on/off switch/disconnect incorporated.

However, looking at the manual for the typical switch, this is probably not the case. (http://www.intermatic.com/~/media/files/intermatic/products/instructions/timers/wh40 - english.ashx)
 
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rich000

Senior Member
Jim W in Tampa said:
And just what good will pad lock do if time motor is running ?
Click to expand...

Nothing. I was just pointing out that it had provisions for a lock. We already established that the motor would still run.

You could take off the pegs, turn off the switch, and lock the door.
 
Dennis Alwon

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
tom baker said:
This time switch does not meet the requirements added in the 2008 NEC see 430.227
Click to expand...

Section 430.227 is for over 600 Volts however it also applies to under 600V in art. 430.102(B)(2).

Now art. 430.109 discusses the type of disconnects allowed and I don't see a timer as listed. I vote it is not allowed.
 
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rich000

Senior Member
Dennis Alwon said:
Section 430.227 is for over 600 Volts however it also applies to under 600V in art. 430.102(B)(2).

Now art. 430.109 discusses the type of disconnects allowed and I don't see a timer as listed. I vote it is not allowed.
Click to expand...

What if it is labeled ?Suitable as Motor Disconnect??
 
S

Strife

Senior Member
No.
The means of disconnect can not automatically turn on.
One can say that the on/off tabs can be removed. I can go and take the wires apart from a photocell. Does that make it a means of disconnect?

clarice said:
This heater is in an outdoor shed and it is attached to a solar water heating system. The panel and breaker are out of sight. There is a manual override on the timer, but it does have the tabs that click it off and on so.....even when placed manually in "off" the timer tabs could click back on....I'm thinking I should use installed a separate disconnect. What is the view of our esteemed council?:confused:
Click to expand...
 
kbsparky

kbsparky

Senior Member
Location
Delmarva, USA
Time clocks are not approved as a required disconnecting means.

Had a customer once, who switched off his timer, and then drained his water heater tank (an annual chore).

He got distracted, and took too long to finish the job. The timer switched power back on to his empty water heater before he could refill the tank.

Long story short, I ended up having to change out one of his elements, since it melted down by being energized without being immersed in water.
 
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