Hi Matt and Lauren:
Lockable breaker panels are de riguer in industrial
environments, for lighting and similar circuits. But I would
counsel against prescribing or approving a lockable panel cover
as a lockout device for any other apparatus, regardless of how
one might reasonably parse 29 CFR 1910 (OSHA).
If the only breaker in the panel is for the apparatus in
question, it is reasonably foreseeable the lockable panel cover
would be locked ON, prevent disconnection, and result in loss or
injury. If the are other breakers in the panel, then they
provide "temptation" to open the panel when it is supposedly
"locked OFF," with resulting accidental electrocution/startup.
I don't know if there is an OSHA clause requiring a
lockable disconnect, addressed to the apparatus Lauren has in
mind. But where the apparatus is such that safety dictates the
presence of a switch disconnect, it is common practice to provide
a disconnect device that is capable of being locked ONLY in the
open position, evidenced by clauses in various standards of
general applicability. I.e., if "lockable cover as
lockout/lockable disconnect" is ever the focus of litigation,
your client will probably lose.
Note that OSHA applies to the workplace, and is not
directly applied to the machine/device builder. However, the
machine/device operator (owner) typically expects the supplier to
provide a machine that is "OSHA compliant." In at least one
circumstance, OSHA does require a lockable disconnect device in
the final installation.
The following applies to mechanical power presses:
29 CFR 1910.217 (b)(8)(i) A main power disconnect switch capable
of being locked only in the Off position shall be provided with
every power press control system.
Voluntary standards NFPA 79 and EN 60204-1 apply to
industrial equipment (typically connected to mains with fixed
wiring), and may or may not be applicable to the apparatus Lauren
has in mind. Based on the type of device typically in the scope
of EN 61010 and 60335 (cord connected apparatus), I would not
expect to read a requirement for a lockable disconnect in either
of them.
Clause 7.10.3 of NFPA 79 says, "The operating handle [of the
disconnecting means] shall be capable of being locked only in the
open (off) position."
Clause 5.3.3 of EN 60204-1 says a switch disconnector (including
circuit breakers used as disconnect) must meet several
requirements, among them, "be provided with with a means
permitting it to be locked in in the OFF (isolated) position
(e.g. by padlocks)"
Clause 6.12.3.1 of EN 61010-1 requires switches/breakers used for
disconnect to comply with IEC 947-1 and IEC 947-3. I doubt, but
don't know for certain, if either of the referenced IEC standards
include a requirement for the switch/breaker being lockable only
in the open position.
Regards,
Chuck Seyboldt
At 10:37 (-0000) on 02.09.20, [email protected] wrote:
> Hi Lauren,
>
> You didn't provide sufficient information regarding the
> application so I can't say much about tagout.
>
> As for lockout: 29 CFR 1910.147 The control of hazardous
> energy (lockout/tagout) pretty clearly rules out performing
> lockout by locking a cover.
>
> Lockout is defined as "The placement of a lockout device on
> an energy isolating device, in accordance with an established
> procedure, ensuring that the energy isolating device and the
> equipment being controlled cannot be operated until the
> lockout device is removed."
>
> A lockout device is defined as A device that utilizes a
> positive means such as a lock, either key or combination
> type, to hold an energy isolating device in the safe position
> and prevent the energizing of a machine or equipment.
>
> A breaker panel cover is not a lockout device applied to an
> energy isolating device. It does not "hold the energy
> isolating device in the safe position".
>
> Under certain circumstances I can see where locking the cover
> might provide "equivalent protection" as required for a
> tagout approach. Under other circumstances (remote closing,
> lockout locks not individually assigned) it might be inviting
> an accidental electrocution or startup. For this reason, the
> method you propose is installation specific.
>
> Additionally, I fail to see the need for such a method, as
> since 1990 it is required that "whenever replacement or major
> repair, renovation or modification of a machine or equipment
> is performed, and whenever new machines or equipment are
> installed, energy isolating devices for such machine or
> equipment shall be designed to accept a lockout device".
>
> Regards,
>
> Matthew Meehan
>
> PS Gruss an FP
>
>
> Original Message processed by Tobit InfoCenter
> Subject: Breaker panel lockout-tagout (18-Sep-2002 19:29)
> From: [email protected]
> To: [email protected]
>
>
> Group,
> Is anyone aware of an authoritative position on the
> acceptability (or not) of applying a lock to a breaker panel
> cover (and so affecting access to other, unrelated, breakers
> behind the same cove) to achieve OSHA compliant
> Lockout/Tagout rather than applying the lock to breaker
> directly?
> -Lauren Crane
> TUV America
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