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•
A nonprofit organization established in 1894 by the
American association of fire insurance companies.
Underwriters Laboratories (abbreviated to UL hereafter)
conducts certification testing on all kinds of electrical
products. In many U.S. cities and states, UL certification is
legally required on all electrical items sold. To obtain UL
certification on an electrical product, all major internal
components also require UL certification.
•
UL offers two types of certification: the Listing Mark and the
Recognition Mark. A Listing Mark generally constitutes the
certification of a final product. Products display the Listing
Marks shown below. The Recognition Mark applies to the
components used in a product, and therefore constitutes a
more conditional approval of a product. Products display
the Recognition Marks shown below. Depending on a
component's UL classification, use of the Recognition
Mark may not be required.
•
UL has integrated its standards with CSA to employ a co-certification system.
These standards also adapt the requirements of the IEC standards.
•
Since October 1992, UL has been recognized as a CO (council organization)
and TO (test organization) by the SCC (Standard Council of Canada). This
authorizes UL to conduct safety tests and certify products conforming to
Canadian standards.
•
The designs of the Listing and Recognition Marks were changed in January
1998 as shown below.
LISTING MARK
RECOGNITION MARK
■
Sensors with DC Power Supply of 30 V or Less
1. When connected to one of the circuits (Class 2) described in (1), (2), and (3)
below, a sensor can be used even if it is not UL certified. Use the following
UL-certified products for combining DC power supplies.
(1) Limited voltage and current circuits according to UL508
Circuits taking as a power supply the secondary winding of an isolation
transformer satisfying the following conditions:
•
A maximum voltage (with no load) of 30 Vrms (42.4 V peak).
•
A maximum current (1) of no more than 8 A (including short-circuiting)
or (2) limited by a circuit breaker (such as a fuse).
(2) Class 2 Power Supply Unit according to UL1310
(3) Circuits with a maximum voltage of 30 Vrms (42.4 V peak) taking a Class
2 transformer as a power supply according to UL1585
2. If a sensor with UL-certified DC power supply specifications is required, a
UL Mark can be affixed to the model in the following table under the
condition that it be used in a Class 2 circuit.
Product Certified for Use in Class 2 Circuits Only (Listing/Recognition
Certification)
*
Recognition Marks are not displayed for recognition certification of DC sensors. Only Listing
Marks are displayed when UL marking is requested.
UL Standards (UNDERWRITERS LABORATORIES INC.)
Marks for US
Marks for Canada
Marks for US and Canada
Marks for US
Marks for Canada
Marks for US and Canada
No-load voltage (V peak)
Maximum rated current (A)
0 to 20
5.0
From 20 to 30
100
Peak voltage
Model
File No.
Listing
certification
Recognition
certification
EE-S Series
*
E41515
O
LISTING MARK
RECOGNITION MARK
In the interest of product improvement, specifications are subject to change without notice.
