Reason for Heater Disconnect??

[brother]

Does anyone really know the reason for them adding the change in 424.19 NEC 2008 for the fixed electric space heating??

Was there really that many accidents to feel there needs to be a 'permanant means to lock it out' on the breaker??

 

[cadpoint]

Let's go with the thought of the broad "Safe" aspects of things, for a minute.

This is one of those device's that can use all the input power, and could use all that it gets.

There's several different devices in the House, or even on the Commerical side, that have this required protection already, HVAC out door and or indoor HVAC, WH, etc., etc. Just think of all the places that this requirement already exists...

It was probably argued to include this one additional device to make it compliant to other application's where alot of power can exist!

Besides these other also include lockout, tag out, and their various requirements.

Creat and Work with-in this Safe Enviroment!

Besides, we need everyone, everyday to return safely, to their other Life!

 

[iwire]

From the 2008 ROP

Substantiation:

The problem with the present wording of this section is that the disconnect in many Fixed Electric Space-Heating Equipment applications is a circuit breaker in a panelboard or a switch that is not made with permanent provisions for locking the circuit breaker or switch in the open position.

This requirement for a disconnect is for the safety of the installer/maintainer of the equipment. Permanent provisions for making circuit breakers and switches capable of being locked in the open position are readily available from circuit breaker and switch manufacturers.


This proposal does not represent a large increase in the cost of an installation but will result in a dramatic increase in safety. Where Fixed Electric Space-Heating Equipment is involved we know that maintenance will take place, we must ensure that only a lock is needed by an installer/maintainer to work safely.

The practical safeguarding of persons from electrical hazards as detailed in the scope of the NEC must not be permitted to hinge on whether or not an installer just happens to have enough different types of devices and hopefully one that that happens to fit the circuit breaker or switch in an installation. Note that this language was accepted by CMP-11 and is a present requirement, in the 2002 NEC, when a circuit breaker or switch is used as a disconnecting means not within sight of a motor. Also included in the 2005 NEC is the same language in 422.31 for appliances

The same level of safety is needed for these disconnecting means for Fixed Electric Space-Heating Equipment.

 

[partimer31]

Does means, heaters operating on a 240 volt. circuit, within a room, that
are controlled by a wall mounted double pole thermostat that has an off
position, that break both legs of the 240 volts circuit, are no longer
allowed?

 

[tom baker]

The thermostat was never a disconnect, a lockout device is required at the panel.

 

[iwire]

The thermostat was never a disconnect, a lockout device is required at the panel.

Tom, The thermostats may still serve as the disconnecting means, check out 2008 424.20(A).

 

[LarryFine]

The thermostat was never a disconnect, a lockout device is required at the panel.

They are if they break all poles and are marked with an 'off' position.