ASTM F1207M-12(2018)

• Abstract:

  ABSTRACT; This specification covers the requirements and testing procedures for five types of electrical insulation monitoring devices intended as permanently installed units that are used in the detection of ohmic insulation faults to ground in active AC ungrounded electrical systems. This specification does not address devices which are not intended for DC or AC ungrounded systems that operated with DC components, unless AC to DC conversion is isolated from the monitored system with transformers. Information required in the equipment manual that shall be provided with this system are also detailed.; SCOPE; 1.1 This specification covers electrical insulation monitoring devices intended as permanently installed units for use in the detection of ohmic insulation faults to ground in active AC ungrounded electrical systems. ; 1.2 Limitations—This specification does not cover devices which are not intended for operation for: DC ungrounded systems or AC ungrounded systems with DC components unless AC to DC conversion is isolated from the monitored system with transformers. ; 1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are included for information only and are not considered standard. ; 1.4 The following precautionary caveat pertains only to the test methods portion, Section 9, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. ; 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

• Status: Published
• Publication Date: 31-Mar-2018
• ICS: 17.220.20 - Measurement of electrical and magnetic quantities
• ICS: 29.080.10 - Insulators
• Technical Committee: F25 - Ships and Marine Technology
• Drafting Committee: F25.10 - Electrical

• Replaces: ASTM F1207M-12 - Standard Specification for Electrical Insulation Monitors for Monitoring Ground Resistance in Active Electrical Systems [Metric]
• Effective Date: 01-Apr-2018

Overview

ASTM F1207M-12(2018) is the internationally recognized standard specification for electrical insulation monitors designed to detect ohmic insulation faults to ground in active AC ungrounded electrical systems. Published by ASTM International, this standard defines the requirements, performance, and testing protocols for five types of permanently installed insulation monitoring devices, ensuring effective detection of insulation degradation and enhanced electrical system safety. The standard applies to metric units and emphasizes both product reliability and operational safety.

Key Topics

• Scope of Application: Focuses on insulation monitors for ungrounded AC systems, including systems operating at voltages up to 1000 V and frequencies between 50 and 400 Hz. DC systems and AC systems with DC components are excluded unless specific transformer isolation is implemented.
• Types of Monitors: Specifies five classifications based on voltage, phase (single or three-phase), and frequency requirements.
• Performance Requirements:
  • Monitors must provide reliable detection of ground faults via continuous or on-demand monitoring.
  • Integrated or external visual and auditory alarms to indicate resistance drops below preset or adjustable response values.
  • Minimum requirements for internal DC and AC resistance to ensure accuracy and safety.
  • Temperature performance range between 0°C and 50°C.
• Product Marking and Documentation: Essential labeling includes manufacturer, model type, voltage and frequency rating, response values, and connection diagrams. An accompanying manual must detail operation, resistance values, test procedures, and safety warnings.
• Testing Methods: Describes type and production tests to validate response accuracy, electrical withstand, and instrument calibration. Requires verification of built-in test device functionality.
• Safety Guidelines: Users are responsible for ensuring compliance with safety, health, and environmental regulations when applying the standard.

Applications

ASTM F1207M-12(2018) provides practical value for a wide range of industries that rely on the safe and continuous operation of ungrounded AC electrical systems. Key application areas include:

• Shipboard and Marine Electrical Systems: Enhances fault detection and safety for vessels where ungrounded AC systems are prevalent.
• Industrial Facilities: Applicable in manufacturing plants, chemical processing, and other settings using ungrounded AC systems for critical operations.
• Infrastructure and Utilities: Suitable for monitoring high-reliability power distribution environments and critical infrastructure.
• Automated and Remote Systems: Supports integration with alarm and monitoring networks to enable timely isolation and maintenance of electrical faults.

The use of standardized insulation monitors helps organizations proactively identify potential ground faults before they escalate, reducing downtime, supporting regulatory compliance, and protecting personnel and equipment.

Related Standards

• UL 1053: Ground-Fault Sensing and Relaying Equipment - Referenced for creepage and air gap separation requirements for voltages up to 300V.
• IEC 664: Insulation Coordination within Low-Voltage Systems - Provides coordination guidelines for higher nominal voltages, including clearances and creeping distances for equipment.
• ASTM F25 and Subcommittee F25.10: Covers standards for ships and marine technology, directly supporting marine applications of insulation monitors.

Summary

Implementing ASTM F1207M-12(2018) ensures that electrical insulation monitors for ungrounded AC systems are properly specified, tested, and maintained. Adopting these guidelines enhances electrical safety, system reliability, and regulatory compliance across a broad array of industrial and marine applications, underlining the importance of robust ground fault detection and response procedures.

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F1207M −12 (Reapproved 2018) An American National Standard
Standard Specification for
Electrical Insulation Monitors for Monitoring Ground
Resistance in Active Electrical Systems (Metric)
This standard is issued under the fixed designation F1207M; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This specification covers electrical insulation monitor- 3.1 Definitions:
ing devices intended as permanently installed units for use in 3.1.1 AC internal resistance—a monitor’s impedance be-
the detection of ohmic insulation faults to ground in activeAC tween the measuring terminals and ground terminals.
ungrounded electrical systems.
3.1.2 AC ungrounded electrical system—a monitored sys-
tem that has no intentional connection from phase or neutral to
1.2 Limitations—This specification does not cover devices
ground and can continue to perform normally if one conductor
which are not intended for operation for: DC ungrounded
becomes connected to ground.
systems or AC ungrounded systems with DC components
unless AC to DC conversion is isolated from the monitored
3.1.3 DC internal resistance—a monitor’s ohmic resistance
system with transformers.
between the measuring and ground terminals.
1.3 The values stated in SI units are to be regarded as
3.1.4 input voltage—the supply voltage at the terminals of
standard. The values given in parentheses after SI units are
an insulation monitor.
included for information only and are not considered standard.
3.1.5 measuring voltage—the output DC voltage from the
1.4 The following precautionary caveat pertains only to the
insulation monitor that is superimposed between the AC
test methods portion, Section 9, of this specification: This
ungrounded system and ground.
standard does not purport to address all of the safety concerns,
3.1.6 nominal contact voltage—the voltage rating for a
if any, associated with its use. It is the responsibility of the user
monitor’s internal relay contacts.
of this standard to establish appropriate safety, health, and
3.1.7 nominal frequency—the frequency of a monitored
environmental practices and determine the applicability of
system.
regulatory limitations prior to use.
3.1.8 nominal voltage—the voltage (phase-to-phase) of a
1.5 This international standard was developed in accor-
monitored system.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
3.1.9 response value—the adjustable or preset set point
Development of International Standards, Guides and Recom-
value of system insulation resistance for which an insulation
mendations issued by the World Trade Organization Technical
monitor will provide alarm indication.
Barriers to Trade (TBT) Committee.
3.1.10 system insulation resistance—the total insulation re-
sistance to ground to be monitored, which is measured by DC
2. Referenced Documents
voltage.
2.1 UL Standard:
UL1053Ground-Fault Sensing and Relaying Equipment 4. Monitor Classification
4.1 Type 1—Insulationmonitorfor115-V,3-phaseorsingle-
phase, 60-Hz, AC ungrounded electrical systems.
4.2 Type 2—Insulationmonitorfor115-V,3-phaseorsingle-
phase, 400-Hz, AC ungrounded systems.
1 4.3 Type 3—Insulationmonitorfor440-V,3-phaseorsingle-
This specification is under the jurisdiction ofASTM Committee F25 on Ships
and Marine Technology and is the direct responsibility of Subcommittee F25.10 on phase, 60-Hz, AC ungrounded systems.
Electrical.
4.4 Type 4—Insulationmonitorfor440-V,3-phaseorsingle-
Current edition approved April 1, 2018. Published May 2018. Originally
approved in 1989. Last previous edition approved in 2012 as F1207M–12. DOI: phase, 400-Hz, AC ungrounded systems.
10.1520/F1207M-12R18.
4.5 Type 5—Insulationmonitorforupto1000-V,3-phaseor
Available from Underwriters Laboratories (UL), 2600 N.W. Lake Rd., Camas,
WA 98607-8542, http://www.ul.com. single-phase, 50 to 400-Hz, AC ungrounded systems.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1207M − 12 (2018)
5. Ordering Information 6.12 Built-in relays for connection to external alarms shall
have a switching capacity of at least 2Aat 250-VAC or 0.5A
5.1 Monitoring devices shall be ordered by specifying the
at 120-V DC.
following information:
6.13 Between isolated, outgoing circuits and between these
5.1.1 Nominal voltage and frequency.
circuits and extraneous conductive parts, insulation monitors
5.1.2 Response value/set point range in kilohm.
shall have creepage and air gap separation in accordance with
5.1.3 Special options, that is, test buttons, ohmeters, visual
UL1053forvoltagesupto300V.Forhighernominalvoltages,
indicators, and so forth.
see IEC Report 664.
6. Requirements
7. Product Marking
6.1 The measuring voltage shall not increase more than
7.1 The following data shall be identified on an insulation
10% when the monitor is supplied with 110% of the input
monitor’s enclosure:
voltage.
7.1.1 Name of manufacturer.
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)audibleorvisualalarmtooperatewhentheresistance
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 theAC ungrounded system in kilohms,
7.1.8 Test resistance value in accordance with 6.9.
or both.
7.1.9 Serial number, or year of production.
6.4 The AC internal resistance shall be at least 250-Ω/V
8. Equipment Manual
nominalvoltage.Theminimumresistanceshallnotbelessthan
15 kΩ.
8.1 The manufacturer’s equipment manual shall provide the
following information in addition to that required in 7.1:
6.5 The DC internal resistance shall be at least 30-Ω/V
8.1.1 Description of operation.
nominal voltage and shall limit the measuring DC output
8.1.2 Values for AC and DC internal resistance.
current from exceeding 12 mA.
8.1.3 Connection diagram. Clearly identify where the con-
6.6 The monitor’s response tolerance shall not exceed
nections are to be made to the equipment being monitored.
65%ofthesetpointvalueatroomtemperature(25 65°C(72
8.1.4 Nominal value of DC measuring voltage, based
...