ASME A17.5 pdf download.Elevator and escalator electrical equipment.
4.3.3
With reference to Tables 1 and 2, a supporting frame shall consist of a structure of angles, channels, or folded rigid sections of sheet metaL This structure shall be rigidly attached to and shall have essentially the same outside dimensions as the enclosure surface and sufficent torsional rigidity to resist the bending moments that m be applied by the enclosure surface when It Is deflected. A structure that Is as rigid as one built with a frame of angles or channels is considered to have equivalent reinforcing. Constructions without a supporting frame shall be considered to Include
(a) a single sheet with single-formed flanges or formed edges;
(b) a single sheet that Is corrugated or ribbed;
(C) an enclosure surface loosely attached to a frame (e.g., with spring clips); and
(d) an enclosure surface having an unsupported edge.
5 Doors and covers
S. I
A part of the enclosure, such as a door or a cover, shall be provided with the means, such as latches or screws, to firmly secure it in place.
Barriers shall be installed to prevent contact with live parts if inadvertent contact with bare live parts during normal service and adjustment operation is considered probable.
Note Troubleshooting or the replorement at fuses is not considered a normal service oument operation with respect to control equipment, but the resetting of overload devices, adjustment a! timers or switches, etc., are considered normal service operations.
6 Polymeric enclosures
Polymeric enclosures shall comply with the conduit connechon test of CSA C22.2 No. 14 or UI 508.
6.2
The thickness of a polymerk enclosure shall be such that the enclosure is sufficiently rigid to support the device and components that will be mounted on it.
6.3
6.3.1
Polymeric enclosure material shall be rated 5 VA (in accordance with CAN/CSA-C22.2 No. 0.17 or
ANSI/Ui 94) or the enclosures shall comply with the requirements of Clause 6.3.2 of this Standard after
testing in accordance with Clause 6.3.3 or 6.3.4 of this Standard.
jj1Jcfulfill the requirements of the tests specified in Clause 6.3.3 or 6.3.4,
the enclosure material shall not continue to burn for more than 60 s after the fifth application of the
test flame;
particles shall not drip from the test sample at any time during the test; and
(C) the material shall not be destroyed in the area of the test fLame to the extent that the integrity of the enclosure is affected as determined by Clauses 4.1, 4.2, and 7.1.
13 Protection of control circuits
13.1 Control circuit conductor protection
Conductors of control circuits that are connected to the load side of the motor branch circuit short-circuit protective device (common control) and that extend beyond the control equipment enclosure shall be protected against overcurrent. in accordance with their ampacities, by protective devices located within the controller; otherwise, the controller shall be marked in accordance with Clause 20.19. Additional protection or additional marking shall not be required if the rating or setting of the intended motor branch circuit short-circuit protective device is not more than 300% of the ampacity (15 A minimum) of the control circuit conductors.
13.2 Control circuit transformer protection
13.2.1
A control circuit transformer shall be provided with one or more of the following types of overcurrent
protection:
(a) individual overcurrent devices located in the primary circuit that are rated or set as specified in Table 7;
(b) secondary circuit protection rated or set at not more than 125% of the rated secondary current of the transformer, with the protection of the primary feeder circuit rated or set at not more than 250% of the rated primary current of the transformer; or
(c) coordinated thermal overload protection arranged to interrupt the primary circuit, provided that the primary circuit overcurrent device is rated or set at a current of not more than
(i) six times the rated current of the transformer for transformers having not more than 6% impedance; or
(ii) four times the rated current of the transformer I or transformers having more than 6% but less than 10% impedance.
13.2.2
Notwithstanding Clause 13.2.1 • overcurrent protection need not be provided if the
(a) transformer supplies a Class 2 circuit
(b) transformer is rated less than 50 VA and is an integral part of the motor controller, and there is no fire hazard (emission of flame or molten material) with a short-circuit on the secondary;
(c) primary feeder circuit overcurrent device provides the required protection; or
(d) protection is provided by other means that comply with the applicable e4ectrical code.
ASME A17.5 pdf download
