You're right to be looking for the Withstand and Close Rating (WCR) specifically for Service Entrance Rated (SER) ASCO Series 300 and 7000 transfer switches. This information is crucial for proper overcurrent protection and ensuring the switch can handle fault currents.Here's a breakdown of where to find the information and the challenges you're likely facing

Where to Look and How to Approach ASCO:

1. ASCO Direct Contact is Key

You are correct that the final authority on the WCR for service entrance applications is ASCO. Reach out to them directly. Here's why this is important:

Specific Application Matters

The WCR can be influenced by exactly how the transfer switch is installed, the type of upstream overcurrent protective device (OCPD), and the system voltage. ASCO needs to know your specific configuration to provide the correct WCR.

Recent Changes

As you noted, there have been recent announcements and updates to WCRs, which means older documentation might not be accurate.

Custom Configurations

Service entrance applications can sometimes involve non-standard configurations. ASCO might have to perform a short-circuit analysis to determine the WCR in these cases.When you contact ASCO, have the following information ready:

Model Number

The exact model number of the ASCO 300 or 7000 switch you're using.

Ampacity

The ampacity rating of the switch.

Voltage

The system voltage (e.g., 480V, 208V).

Upstream OCPD

The manufacturer, model number, and interrupting rating of the circuit breaker or fuse protecting the transfer switch.

Installation Details

A description of the installation, including conductor sizes, lengths, and any other relevant factors. If possible, a single-line diagram is helpful.How to contact ASCO:

ASCO Website

Use the "Contact Us" or "Support" section of the ASCO Power Technologies website ([https://www.ascopower.com/](https://www.ascopower.com/)). Look for a way to submit a technical support request.

Local ASCO Representative

Find your local ASCO sales representative. They will have direct access to the engineering resources needed to answer your question.

Phone

Call ASCO's customer support line. Be prepared to provide the information listed above.2.

ASCO Documentation (with Caution)



Installation Manuals

Carefully review the installation manuals for the specific model number. Sometimes the WCR information is included in a table within the manual. However, always verify this information with ASCO due to the factors mentioned above. Look for a table specifically titled "Withstand and Close Rating" or "Short-Circuit Current Rating."

Technical Data Sheets

Check ASCO's website for technical data sheets for the specific models. Again, verify this information with ASCO.

Why Finding General Information is Difficult



Application-Specific Rating

As mentioned, the WCR for service entrance applications is highly dependent on the specific installation. ASCO cannot provide a single "blanket" rating that applies to all situations.

Liability

Providing an incorrect WCR could lead to equipment damage, injury, or even death. ASCO is very cautious about providing this information and will usually require detailed information about the installation.

Testing Standards

The testing standards for service entrance equipment are stringent. ASCO may have conducted tests under specific conditions that they need to correlate with your application.

Key Considerations When Evaluating the WCR



Series Ratings

ASCO may provide a "series rating" that allows a lower-rated transfer switch to be used with a higher-rated OCPD if certain conditions are met. Carefully review the conditions of the series rating to ensure they are satisfied.

Fuse vs. Circuit Breaker

The WCR can be different depending on whether the upstream OCPD is a fuse or a circuit breaker.

UL 1008

ASCO transfer switches are typically UL 1008 listed. This standard covers the performance and safety requirements for transfer switches, including short-circuit current ratings. Make sure the switch is properly listed.

UL 67 Panelboard that contains the service entrance rated transfer switch is also subject to the WCR testing. (Confirm with the manufacturer)In Summary:

The best approach is to gather all the necessary information about your specific installation and contact ASCO directly for the WCR of your ASCO Series 300 or 7000 service entrance transfer switch. Do not rely solely on general information or outdated documents. Verify all information with ASCO.Good luck! Flag for review