3.4.7 CETP Instructor PowerPoint Template

1
Prevention of gas ignition in transfer areas is
partially accomplished by the installation of
properly selected electrical equipment and wiring
.

• In this module you will learn to identify
• Regulations that pertain to propane bulk plant
  electrical systems
• Basic considerations for bulk plant electrical
  systems

2
Code Requirements for Propane Bulk Plant
Electrical Systems
3.7.2.1 Electrical equipment and wiring shall be
of a type specified by, and installed in
accordance with NFPA 70, National Electrical Code
(NEC). 3.7.2.2 Fixed electrical equipment and
wiring installed within classified areas
specified in Table 3.7.2.2 shall comply with
Table 3.7.2.2 and shall be installed in
accordance with NFPA 70, National Electrical
Code. Article 500 of NFPA 70, provides
definitions of Division 1, and Divisions 2 areas
requiring special attention to electrical
equipment and wiring
NFPA 70
3
Basic Considerations for Bulk Plant Electrical
Systems

• When making modifications or changes to a bulk
  plant wiring system, always use a licensed
  electrician.
• Electrical control switches and wiring must
  conform to NFPA 70 NEC. Class I, Group D,
  Division 1 or 2 Installations.
• Pump and compressor switches must be readily
  available to the dispenser operator.
• Electrical control switches for dispenser pumps
  are typically heavy-duty single pole/single throw
  switches, similar to light switches, and mounted
  in a Class I, Group D, Division 1 or 2 explosion
  proof fixture.

4
Basic Considerations for Bulk Plant Electrical
Systems
Figure 1a Readily Accessible Pump Switch
Figure 1b. Explosion Proof Switch Fixture
5
Basic Considerations for Bulk Plant Electrical
Systems

• OSHA requires that all electrical controls for
  equipment must be clearly marked and/or
  color-coded to indicate the on and off (stop)
  positions. The color designated for the off or
  stop position is red.
• Safety codes require an electrical emergency shut
  down be located more than 20 feet (but less than
  100 feet) from the dispenser, and prominently
  labeled.
• All electrical wiring in Division 1 or 2 areas
  must be installed in rigid conduit, Class I,
  Group D and in flexible sections.
• A seal-off fixture (commonly referred to as an
  EYS or Electrical Wye Sealoff) filled with a
  suitable putty must be installed between the
  dispenser area and the main electrical supply.

6
Basic Considerations for Bulk Plant Electrical
Systems
Figure 3. Seal-off Fixtures to Prevent Propane
Vapor from Entering Open Wiring
Figure 2. Class I, Group D Wiring Conduit, Flex
Section and Fixtures
7
Basic Considerations for Bulk Plant Electrical
Systems

• Large pumps and compressors require magnetic
  starters and a 3-phase power source.
• Caps on all fixtures must always be in place and
  securely tightened. All electrical wiring in
  Division 1 or 2 areas must be installed in rigid
  conduit, Class I, Group D and in flexible
  sections.
• All fixture bolts must be in place and securely
  tightened.
• Never paint over a plate or label.
• KEEP ELECTRICAL SYSTEMS UP TO CODE.

8
Time to See If You Got the Key Points of This
Module

• Complete the Review on page 4.
• See if you are ready for the Certification Exam
  by checking off the performance criteria on page
  5.