ASTM F1207M-96(2002)

An American National Standard
Designation: F 1207M – 96 (Reapproved 2002)
METRIC
Standard Specification for
Electrical Insulation Monitors for Monitoring Ground
Resistance in Active Electrical Systems [Metric]
This standard is issued under the fixed designation F 1207M; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope between the measuring and ground terminals.
3.1.4 input voltage—the supply voltage at the terminals of
1.1 This specification covers electrical insulation monitor-
an insulation monitor.
ing devices, intended as permanently installed units, for use in
3.1.5 measuring voltage—the output dc voltage from the
the detection of ohmic insulation faults to ground in active, ac
insulation monitor that is superimposed between the ac un-
ungrounded electrical systems.
grounded system and ground.
1.2 Limitations—This specification does not cover devices
3.1.6 nominal contact voltage—the voltage rating for a
which are not intended for operation for: dc ungrounded
monitor’s internal relay contacts.
systems or ac ungrounded systems with dc components unless
3.1.7 nominal frequency—the frequency of a monitored
ac to dc conversion is isolated from the monitored system with
system.
transformers.
3.1.8 nominal voltage—the voltage (phase-to-phase) of a
1.3 The values stated in SI units are to be regarded as the
monitored system.
standard. The values given in parentheses are for information
3.1.9 response value—the adjustable or preset set point
only.
value of system insulation resistance for which an insulation
1.4 The following precautionary caveat pertains only to the
monitor will provide alarm indication.
test methods portion, Section 9, of this specification: This
3.1.10 system insulation resistance—the total insulation
standard does not purport to address all of the safety concerns,
resistance to ground to be monitored which is measured by dc
if any, associated with its use. It is the responsibility of the user
voltage.
of this standard to establish appropriate safety and health
practices and determine the applicability of regulatory limita-
4. Monitor Classification
tions prior to use.
4.1 Type 1—Insulation monitor for 115-V, 3-phase or
2. Referenced Documents single-phase, 60-Hz, ac ungrounded electrical systems.
4.2 Type 2—Insulation monitor for 115-V, 3-phase or
2.1 UL Standard:
single-phase, 400-Hz, ac ungrounded systems.
UL 1053 Ground-Fault Sensing and Relaying Equipment
4.3 Type 3—Insulation monitor for 440-V, 3-phase or
3. Terminology
single-phase, 60-Hz, ac ungrounded systems.
4.4 Type 4—Insulation monitor for 440-V, 3-phase or
3.1 Definitions:
single-phase, 400-Hz, ac ungrounded systems.
3.1.1 ac internal resistance—a monitor’s impedance be-
4.5 Type 5—Insulation monitor for up to 1000-V, 3-phase or
tween the measuring terminals and ground terminals.
single-phase, 50 to 400-Hz, ac ungrounded systems.
3.1.2 ac ungrounded electrical system—a monitored system
that has no intentional connection from phase or neutral to
5. Ordering Information
ground and can continue to perform normally if one conductor
5.1 Monitoring devices shall be ordered by specifying the
becomes connected to ground.
following information:
3.1.3 dc internal resistance—a monitor’s ohmic resistance
5.1.1 Nominal voltage and frequency.
5.1.2 Response value/set point range in kilohm.
This specification is under the jurisdiction of ASTM Committee F25 on Ships
5.1.3 Special options, that is, test buttons, ohmeters, visual
and Marine Technology and is the direct responsibility of Subcommittee F25.10 on
indicators, and so forth.
Electrical.
Current edition approved June 10, 1996. Published August 1996. Originally
6. Requirements
published as F 1207 – 89. Last previous edition F 1207 – 89.
Available from Underwriters Laboratories, Inc., 333 Pfingsten Rd., Northbrook,
6.1 The measuring voltage shall not increase more than
IL 60062.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F 1207M
10 % when the monitor is supplied with 110 % of the input 7.1.1 Name of manufacturer.
voltage. 7.1.2 Type of monitor.
6.2 The monitor shall be capable of both continuous and 7.1.3 Connection diagram.
on-demand operation. 7.1.4 Nominal voltage rating.
6.3 The monitor shall have provisions for an external 7.1.5 Input voltage.
(remote) audible or visual alarm to operate when the resistance 7.1.6 Nominal frequency.
value falls below the response value or a remote indication of 7.1.7 Response value or range.
the insulation value of the ac ungrounded system in kilohms, or 7.1.8 Test resistance value in accordance with 6.9.
both. 7.1.9 Serial number, or year of production.
6.4 The ac internal resistance shall be at least 250-V/V
8. Equipment Manual
nominal voltage. The minimum resistance shall not be less than
8.1 The manufacturer’s equipment manual shall provide the
15 kV.
following information in addition to that required in 7.1:
6.5 The dc internal resistance shall be at least 30-V/V
8.1.1 Description of operation.
nominal voltage and shall limit the measuring dc output current
8.1.2 Values for ac and dc internal resistance.
from exceeding 12 mA.
8.1.3 Connection diagram.
6.6 The monitor’s response tolerance shall not exceed
8.1.4 Nominal value of dc measuring voltage, based on
65 % of the set point value at room temperature (25 6 5°C (72
possible supply voltages.
6 9°F)) and rated input voltage.
8.1.5 Maximum dc measurement current at short-circuit
6.7 When specified, insulation monitors shall be furnished
conditions.
with adjustable response values and designed to preclude
8.1.6 Nominal contact voltage and current ratings for inte-
tampering or unauthorized changes.
gral relays in accordance with 6.12.
6.8 The insulation monitor shall reliably function in an
8.1.7 A note advising that external dc voltage applied to the
ambient temperature range from 0 to 50°C (32 to 122°F).
monitor’s measuring terminals may falsify the indication or
Storage temperatures of −20 to +60°C (−4 to 140°F) must not
destroy the insulation monitor.
damage the insulation monitors.
8.1.8 Magnitude of external dc voltages, independent of
6.9 Insulation monitors shall include a built-in test device o
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