SUN - UL 541, Refrigerated Vending Machines

Effective July 22, 2016

Standard Information
Standard Number:
UL 541
Standard Name:
Refrigerated Vending Machines
Standard Edition and Issue Date:
Eighth Edition, Dated December 30, 2011
Date of Revisions:
December 23, 2014
Date of Previous Revisions to Standard:
8th Edition Revised November 6, 2013
Effective Date of New/Revised Requirements

Effective Date (see Schedule below): July 22, 2016

Impact, Overview, Fees and Action Required

Impact Statement: A review of all Listing Reports is necessary to determine which products comply with new/revised requirements and which products will require re-evaluation. NOTE: Effective immediately, this revised standard will be exclusively used for evaluation of new products unless the Applicant requests in writing that current requirements be used along with their understanding that their listings will be withdrawn on Effective Date of July 22, 2016 unless the product is found to comply with new/revised requirements.

Overview of Changes:

Revision and addition of requirements to clarify the differences between requirements that apply to devices that control a motor and devices that provide motor protection, addition and revision of capacitor requirements to allow for compliance with alternative capacitor requirements in the standard for fixed capacitors for use in electronic equipment, UL 60384-14, and revisions to stand-alone solar photovoltaic vending machines requirements for machines not intended to be connected to an electrical production and distribution network.
Specific details of new/revised requirements are found in table below.


Processing Schedule: So that production of products bearing Listing Marks will not be interrupted, the following schedule of approximate dates has been established to ensure Listing Reports are found compliant by Effective Date:

  • November 21, 2015 = 8 Month Report Review – Intertek will review all Reports. Update if compliance is verified or issue Findings Letter/Quote for any re-evaluations needed- 
  • January 22, 2016 = 6 Month Quote Cut-off – Quotes returned for necessary re-evaluations
  • June 24, 2016 = 30 Day Warning – Client advised of all non-compliant Reports to be Suspended
  • July 22, 2016 = Effective Date – ATM Suspended for all non-compliant Reports

Fees: An initial review of Listing Report (s) will be covered by a direct billing project and will be invoiced at not more than $1000 per report.

Client Action Required:

Information - To assist our Intertek Engineer with review of your Certification Reports, please submit technical information in response to the new/revised paragraphs noted in the attached or explain why these new/revised requirements not apply to your product (s).

Current Listings Not Active? – Please immediately identify any current Listing Reports or products that are no longer active and should be removed from our records. We will do this at no charge as long as Intertek is notified in writing prior to the review of your reports.

Description of New/Revised Technical Requirements
16.1.11 (a)(2) 

Added underlined

The means for grounding shall be one of the following:

a) The equipment grounding terminal or lead of a;

1) Permanently installed vending machine; or

2) Vending machine with a stand-alone solar PV system.

b) The equipment-grounding conductor in the cord of a cord-connected vending machine.
16.1.12 Added clause
With reference to 16.1.11(a)(2), a vending machine with a stand-alone solar PV system shall have provision for permanent connection to a grounding means and the equipment grounding connection requirements in 16.3 for permanently connected venders shall be applied except that the vending machine is not required to have a permanent connection to a grounding means or an equipment grounding connection if the vending machine is marked as specified in 99.33.

Added underlined

Except as specified in 16.1.8 or 16.1.9, the size of a conductor or strap employed to bond an electrical enclosure or motor frame shall comply with Table 16.2 for a:

a) Permanently connected vending machine based on the rating of the branch circuit overcurrent device to which the equipment will be connected; and

b) Stand-alone solar PV system vending machine having provision for a permanent connection to a grounding means, based on the rating of the overcurrent protective device required in accordance with 47.5. 

Added clause

With reference to 30.1.14(b), (c) and (g), when determining the acceptability of a protective control, the control pollution degree shall be as specified in 52.3(a) – (d). If the protective control:

a) Has a protective electronic circuit, the items in 29.5.2(a) – (k) shall be considered; and

b) Uses software as a required part of the protective electronic circuit, the software shall comply with 29.5.3(b).

Added clause

Appendix A, specifying the operating and protective (²safety critical²) control functions, shall be referenced to determine whether a control function is considered to result in a risk fire, electrical shock, or injury to persons.

Added underlined

A vender with PV modules or cells shall be provided with a factory installed ground-fault circuit-interrupter (GFCI) complying with the Standard for Ground-Fault Circuit-Interrupters, UL 943. If the

vender is:      

a) Cord-connected, the GFCI shall comply with 15.3 – 15.5; or

b) Intended for permanent connection to the source of electrical supply or is a stand-alone solar PV system, the GFCI shall be in the circuit supplying power from the PV modules or cells

and shall:

1) Automatically disconnect the ungrounded conductors of the faulted circuit; or

2) Enable the inverter or charge controller fed by the faulted circuit to automatically cease supplying power to the output circuits.

Added clause

With reference to 49.1, if a capacitor complies with the Standard for Fixed Capacitors for Use in Electronic Equipment, UL 60384-14, it shall have specifications as follows:

a) Operating voltage – Not less than 110 percent of the vending machine rated voltage.

b) For capacitors connected across the line (phase-to-phase) – Subclass X1 (£ 4.0 kV) or X2 (£ 2.5 kV) for impulse voltage (based on minimum Overvoltage Category of II).

c) For capacitors connected from line to ground – Subclass Y1 or Y2 for any vending machines having a rated voltage not exceeding 500 volts; or as an alternate, subclass Y4 if a vending machine has a rated voltage not exceeding 150 volts.

d) Upper category temperature – Based on the maximum capacitor surface temperature measured during the Temperature and Pressure Test, Section 63 or the Heating Test, Section 65, whichever is higher, but not less than 185°F (85°C).

e) Lower category temperature – Based on the minimum surface temperature for which the capacitor has been designed to operate when installed within a vending machine as intended, but not greater than 14°F (−10°C).

f) Duration of the damp-heat steady-state test – Not less than 21 days.

g) Passive flammability category B or C. As an alternate, a polymeric capacitor case shall have a V-0 flame rating as described in the Standard for Tests for Flammability of Plastic Materials for Parts in Devices and Appliances, UL 94.

Operating and protective (²safety critical²) control functions


CUSTOMERS PLEASE NOTE: This Table and column "Verdict" can be used in determining how your current or future production is or will be in compliance with new/revised requirements.