Sec. 68.302  Environment simulation.

    Registered terminal equipment and registered protective circuitry 
shall comply with all the criteria contained in the rules and 
regulations in this subpart, both prior to and after the application of 
each of the mechanical and electrical stresses specified in this 
section, not withstanding that certain of these stresses may result in 
partial or total destruction of equipment.
    (a) Vibration. The equipment shall be subjected to vibration while 
in the condition that it is normally shipped or transported. That is, 
during the following vibration test the equipment shall be vibrated 
while packaged if shipped packaged, or the equipment shall be vibrated 
while unpackaged if shipped unpackaged. The following sinusoidal 
vibration should be applied once in each of three orthogonal directions, 
however, for large equipments, the unit should rest on the base or side 
on which it is normally shipped: One sweep at a level of 0.5g peak from 
5 to 100 Hz, and one sweep at a level of 1.5g peak from 100 to 500 Hz. 
The 5 to 100 Hz sweep should be conducted at a sweep rate of 0.1 octave/
min. (approximately 45 minutes) and the 100 to 500 Hz sweep at a rate of 
0.25 octave/min. (approximately 10 minutes).
    (b) Temperature and humidity. Cycling at any convenient rate through 
the following temperature and humidity conditions three times: 30 
minutes at 65 deg. C (150 deg. F) and 15 percent relative humidity, 
followed by 30 minutes at 32 deg. C (90 deg. F) and 90 percent relative 
humidity, followed by 30 minutes at -40 deg. C (-40 deg. F) and any 
convenient humidity.
    (c) Shock. (1) Registered Terminal Equipment and Registered 
Protective Circuitry Equipment Unpackaged:
    Hand-Held Items Normally Used at Head Height:
    18 random drops from a height of 150 cm (60 in) onto concrete 
covered with 3 mm (\1/8\ in) asphalt tile or similar surface.
    Normally Customer Carried Equipment:
    6 random drops from a height of 75 cm (30 in) onto concrete covered 
with 3 mm (\1/8\ in) asphalt tile or similar surface.
    Equipment Not Normally Customer Carried:
    These tests are made onto concrete covered with 3 mm (\1/8\ in) 
asphalt tile or similar surface.
    0-10 kg (0-20 lbs): One 15 cm (6 in) face drop on each normal or 
designated rest face, one 7 cm (3 in) drop on all other faces, and one 7 
cm (3 in) corner drop on each corner.
    10-20 kg (20-50 lbs): One 10 cm (4 in) face drop on each normal or 
designated rest face, one 5 cm (2 in) face drop on all other faces, and 
one 5 cm (2 in) corner drop on each corner.
    20-50 kg (50-100 lbs): One 5 cm (2 in) face drop on each normal or 
designated rest face. One edgewise drop and one cornerwise drop from a 
height of 5 cm (2 in) on each edge and corner adjacent to the rest face.
    50-500 kg (100-1000 lbs): One 2 cm (1 in) face drop on each normal 
or designated rest face. One edgewise drop and one cornerwise drop from 
a height of 2 cm (1 in) on each edge and corner adjacent to the rest 
face.
    Over 500 kg (1,000 lbs): One 2 cm (1 in) face drop on each normal or 
designated rest face. One edgewise drop from a height of 2 cm (1 in) on 
each edge adjacent to this rest face.

    (2) The drop tests specified in the mechanical shock conditioning 
stresses shall be performed as follows:

    FACE DROP--The unit should be dropped such that the face to be 
struck is approximately parallel to the impact surface.
    CORNER DROP--The unit should be dropped such that upon impact a line 
from the struck corner to the center of gravity of the packaged 
equipment is approximately perpendicular to the impact surface.
    EDGEWISE DROP--The unit should be positioned on a flat test surface. 
One edge of the rest face should be supported with a block so that the 
rest face makes an angle of 20 deg. with the horizontal. The opposite 
edge should be lifted the designated height above the test surface and 
dropped.
    CORNERWISE DROP--The unit should be positioned on a flat test 
surface. One corner of the test face should be supported with a block so 
that the rest face makes an angle of 20 deg. with the horizontal. The 
opposite corner should be lifted the designated height above the test 
surface and dropped.
    RANDOM DROP--The unit should be positioned prior to release to 
ensure as nearly as possible that for every six drops there is one 
impact on each of the six major surfaces and that the surface to be 
struck is approximately parallel to the impact surface.

    (d) Metallic voltage surge. Two 800-volt peak surges of a metallic 
voltage (one

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of each polarity) having a 10-microsecond maximum rise time to crest and 
a 560-microsecond minimum decay time to half crest applied between (1) 
tip and ring of a 2-wire connection; (2) between tip and ring, and tip 1 
and ring 1 of a 4-wire connection; (3) between tip and tip 1 (with tip 
and ring tied together and tip 1 and ring 1 tied together) of a 4-wire 
connection which uses simplexed pairs for signaling; and (4) any other 
pair of connections on which lightning surges may occur (with one of the 
connections of the pair under test grounded) with the equipment in each 
of the following states:
    (i) Any operational state which can affect compliance with the 
requirements of part 68;
    (ii) Any state in which the equipment might be connected to the 
telephone network and from which it is capable of transferring to an 
operational state by an automatic or manual action required for proper 
use of the equipment and provided that any such state can affect 
compliance with the requirements of part 68; and
    (iii) Any state in which the equipment might be connected to the 
telephone network through an automatic or manual action under all 
reasonably foreseeable possibilities of disconnection of connections of 
such equipment with primary commercial power sources (including possible 
loss of equipment grounding through disconnection of a third-wire ground 
connection contained in a primary power source plug).

All other equipment leads (telephone connections, auxiliary leads, and 
terminals for connection to nonregistered equipment) not being surged or 
connected to those being surged should be terminated in a manner which 
is no less severe than that which occur in normal use and affect 
compliance with subpart D. Also, equipment states which cannot be 
achieved by normal means of power shall be achieved artificially by 
appropriate means, if necessary to comply with the above requirements. 
The peak current drawn from the surge generator must not be limited to 
less than 100 amperes by the capabilities of the surge generator except 
for the simplexed arrangement in case (3), which must not be limited to 
less than 200 amperes.
    (e) Longitudinal voltage surge. With registered terminal equipment 
in each of the following states: first, any operational state which can 
affect compliance with the requirements of part 68, second, any state in 
which the equipment might be connected to the telephone network and from 
which it is capable of transferring to an operational state by an 
automatic or manual action required for proper use of the equipment and 
provided that each state can affect compliance with the requirements of 
part 68 and third, any state in which the equipment might be connected 
to the telephone network through an automatic or manual action under all 
reasonably foreseeable possibilities of disconnection of connections of 
such equipment with primary commercial power sources (including possible 
loss of equipment grounding through disconnection of a third-wire ground 
connection contained in a primary power source plug):
    (1) Two 1500 volt peak surges (one of each polarity) having a 10 
microsecond maximum rise time to crest and a 160 microsecond minimum 
decay time to half crest applied separately between each of the 
following leads individually and (i) and (ii) below, and where 
available, also between all of the following leads tied together and (i) 
and (ii) below: Tip, ring, tip 1, ring 1, M (only for registered 
terminal equipment located on the ``A'' side of a Type I E&M interface).
    (i) Earth ground; and
    (ii) All leads on the registered equipment intended for connection 
to non-registered equipment when these leads are connected together.

The peak current drawn from the surge generator must not be limited to 
less than 200 amperes by the capabilities of the surge generator.
    (2) Two 1500 volt peak surges (one of each polarity) having a 10 
microsecond maximum rise time to crest and a 160 microsecond minimum 
decay time to half crest applied between pairs of connections other than 
tip and ring on which lightning surges may occur, connected together, 
and individually to (i) and (ii) below:
    (i) Earth ground; and

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    (ii) All leads on the registered equipment intended for connection 
to non-registered equipment when these leads are tied together.

The peak current drawn from the surge generator shall not be limited to 
less than 200 amperes by the capabilities of the surge generator.
    (3) Six 2500 volt peak surges (three of each polarity) having a 2 
microsecond maximum rise time to crest and a 10 microsecond minimum 
decay time to half crest applied between the phase and neutral terminals 
of the ac power line. The peak current drawn from the surge generator 
must not be limited to less than 1000 amperes by the capabilities of the 
surge generator.

All other equipment leads (telephone connections, auxiliary leads, and 
terminals for connection to non-registered equipment) not being surged 
or connected to those being surged should be terminated in a manner 
which is no less severe than that which would occur in normal use and 
affect compliance with subpart D. Also, equipment states which cannot be 
achieved by normal means of power shall be achieved artificially by 
appropriate means, if necessary to comply with the above requirements.
    (f) Failure modes resulting from the application of metallic and 
longitudinal surges. Registered terminal equipment and registered 
protective circuitry are permitted to reach a failure-mode state in 
violation of longitudinal balance requirements of Sec. 68.310, and for 
terminal equipment connected to Local Area Data Channels a failure-mode 
state in violation of the longitudinal signal power requirements of 
Sec. 68.308, after application of the electrical surges specified in 
paragraphs (d) and (e) herein, provided that:
    (1) Such failure results from an intentional, designed failure mode 
which has the effect of connecting telephone or auxiliary connections 
with earth ground; and,
    (2) If such a failure-mode state is reached, the equipment is 
designed in such a manner that it would become substantially and 
noticeably unusable by the user, or an indication is given to the user 
(e.g., an alarm), in order that such equipment can be immediately 
disconnected or repaired.

    Note:  The objective of this subsection is to allow for safety 
circuitry which diverts lightning-like transients to earth ground, but 
which may continue to maintain the earth ground connections after the 
transients have ceased. Such a failure-mode has the potential for 
causing interference resulting from longitudinal imbalance, and 
therefore designs must be adopted which will cause the equipment either 
to be disconnected or repaired rapidly after such a state is reached, 
should it occur in service. This subsection does not apply to tie trunk 
interface leads.


[ 45 FR 20853 , Mar. 31, 1980, as amended at  50 FR 47549 , Nov. 19, 1985; 
 51 FR 944 , Jan. 9, 1986;  51 FR 16689 , May 6, 1986;  58 FR 44907 , Aug. 25, 
1993]