Subject 498 September 10, 2008
TO: Electrical Council of Underwriters Laboratories Inc.
SUBJECT: Receptacle with Cam Type Terminal
UL has received a request to investigate both single and duplex receptacles of the
ANSI/NEMA configurations and electrical ratings identified below, which employ a new
form of pressure wire terminal construction being referred to as a “Cam–type” terminal.
ANSI/NEMA WD6 Configuration Electrical Rating
5-15R 15 A, 125 V
5-20R 20 A, 125 V
6-15R 15 A, 250 V
6-20R 20 A, 250 V
The purpose of this bulletin is to solicit your input and opinions, with respect to the use,
and possible misuse, of the subject receptacle, before proceeding with the investigation.
“Cam–Type” Terminal Description:
All receptacle terminals, (line, neutral and grounding) are intended to employ this
terminal design. The manufacturer rates the terminal for use with No. 14 and 12 AWG
solid copper conductors. The installer strips the conductor according to a strip gauge
specified as required in UL 498, Table 163.4 Reference No. 3. The installer disengages
the latch, inserts the stripped conductor into the terminal hole, and activates the cam by
closing the latch and securing it to a notch located on the body. Appendix A, copy
attached, provides pictorials depicting the terminal construction details.
The standard to be used as the basis of this evaluation is UL 498, the Standard for
Attachment Plugs and Receptacles. In addition to the applicable requirements
contained in UL 498, the following additional considerations have been identified:
Connection Reliability: It is anticipated that a receptacle employing this terminal
design (as is the case with present receptacle terminal designs) may be removed
from the branch circuit and re-installed. The integrity of the latching mechanism to
engage and retain the conductor in a fixed position within the terminal is essential to
safety. Based on this terminal design, we intend to perform the UL486A-486B
Standard for Wire Connectors, Current–Cycling test (Section 7.2), Static-Heating
Sequence (Section 7.3), Mechanical Sequence (Section 7.4), Dielectric Voltage
Withstand (Section 7.5), Secureness of Insulation test (Section 7.6), Spring Action
(UL 486C, Section 9.12). For Canadian certification, Low Temperature installation
(UL 486A-486B, Section 7.10) testing will also be required.
September 10, 2008
Installation Instructions: The latching mechanism "snaps" into place with a visible
and audible indication. We anticipate requiring detailed installation instructions for
assembly of conductors to terminals since the wiring method may not obvious to the
installer. Detailed installation instructions are currently required for similar terminal
constructions used for both Wire Connectors and Terminal Blocks certified by UL.
Latch Reliability: We intend to conduct the Latching Mechanism test identified in UL
498, Section 137H (CRD Issued 20080808) to detect possible damage to latching
mechanism as a result of frequent latch operation.
Grounding: - To address reliability of the ground connection with respect to its ability
to carry fault current, we intend to perform Ground Contact Temperature, Resistance
and Short Circuit testing identified in UL 498, Sections 137F, 137G and 137I
respectively, identified in CRD Issued 20080808.
Terminal Identification – UL anticipates requiring that color identification be used to
identify the terminals. Black will identify the ungrounded conductor terminal and
white will identify the grounded conductor terminal, by indicating the color on the
receptacle body adjacent to the terminal and/or by coloring the terminal latch. For
the grounding conductor, it is anticipated that the terminal latch will be required to be
UL anticipates a subsequent UL 498 Standards revision would be pursued. This would
serve to define the cam terminal as “Terminal, cam type - a form of pressure wire
terminal in which securement pressure is applied on conductors by a cam bearing,
either directly or through a wire-protecting pad.” This revision would also document the
additional testing method used to investigate this terminal construction.
UL is requesting that you complete the questionnaire by September 30, 2008.
The information contained herein is confidential, provided in the interest of Council
business, and should not be made available to any other persons.
Report by: Reviewed by:
Chuck Kurten John Thompson
Principal Engineer (PDE) PDE Manager
Wiring Systems & Components PDE Division, 3615ASNK
PDE Division, 3615ASNK
Principal Engineer, North America
September 10, 2008
terminal hole located
in rear body Terminal Latch –
Shown in open &
Rear View –
With rear body removed
Illustrates position of line
terminals & contacts and
Terminal Detail -
Terminal pad is provided
Terminal is also provided
with serrations (not shown)