Commercial Building Solutions

Honeywell main product image
roll over image to zoom in

301EM Expansion Module

301EM Expansion Module acts as a controller for up to twenty remote refrigerant sensors and detects a wide variety of gases.
Features & Benefits
  • Easy to read LCD display
  • Auto-diagnostic capabilities
  • Convenient stand-alone or network operation
Quick Specs
  •  Power requirement: 22-27 VAC, 29-38 VDC, 2A max @ 29 VDC
  •  Size: 11 (H) x 8 (W) x 2.7 (D) in. (28 x 20.3 x 7cm)
  •  Weight: 2.25 lbs. (1.02 kg)
Need Assistance?
Call: +91 (0)124 4752700
Enter your name and phone number and a Honeywell representative will contact you shortly.
SSL Lock SSL Secure
Don't worry, we won't share your phone and email address. (privacy policy)

Product Overview

Easily configured to meet ASHRAE 15, B-52 and International Mechanical Code requirements, the 301EM is commonly used to optimise gas detection in mechanical and chiller rooms.

A full complement of sensors (including toxic, Oxygen, combustible gases and a full line of refrigerant sensors), horns, strobes and remote panels provide added flexibility to suit a variety of gas detection system solutions.

ASHRAE No 15-2001 Mechanical Standard and B-52 Code Compliance
The ASHRAE and B-52 security standards have been established to minimise risk and protect the safety of mechanical room personnel and the environment at large. Available in a special configuration, the 301EM mechanical room controller has been carefully designed to meet and even exceed these rigorous standards. The Vulcain 301EM can be configured to offer automatic fan, horn and strobe activation in addition to manual fan activation. Latching relay for manual alarm recognition, silence key for manual horn deactivation, built-in 24 Vdc outputs for horn operation, and 2 breakglass switch accessories for manual alarm activation ensure optimal performance.

Additional Features and Benefits:

User Friendly
  • Easy to read LCD display
  • Auto-diagnostic capabilities


Economical Solution
  • Cost-effective answer for installation in hazardous locations


Flexible Operation
  • Able to operate with up to twenty remote sensors at a time
  • Various sensors available to simultaneously detect a range of different gases
  • Robust and reliable RS-485 Modbus communication


Output Adaptability
  • Three 24 Vdc alarm outputs and four 4-20 mA outputs


Safety Measures
  • Four fully programmable relays
  • Three alarm levels with built-in visual indicators and audible alarm


Beneficial Options
  • Convenient stand-alone or network operation
Optimize gas detection in chiller rooms with 301EM Expansion Module - Honeywell Analytics

Frequently Asked Questions

Have a question about the product features or warranty? Find the answers here.
We do not sell our products directly on our website but we would be happy to assist you with your gas detection needs.  On each product page you will see a red button on the right-hand side titled “HOW TO BUY”.  If you click on this button a form will appear which will go directly to one of our sales representatives once completed and submitted.  

You can also call one of our sales representatives directly.  Click here to go to the Contact Us page.  

There are two areas where you can access technical documents.  First, you can visit our Technical Library in the Support section of the website.  Here you will be able to access our entire catalog of documents and videos for all products – current and legacy products.  

You can also access the technical documents for each product on that product’s respective page within the website.    

Yes we do.  Check out our HA University training section to see what programs are available and sign up for any that you are interested in.  These courses are very informative and led by our expert engineers.  If you have any questions about training opportunities for yourself or your staff and would like to talk to a Honeywell representative, click here.

Check out the Product Inquiry page in the Contact Us section.  Here you’ll find sales contacts for each of our product lines and they can help you with any questions you may have from technical specifications to ordering information. 

Check out the Service & Repairs page in the Contact Us section.  Here you’ll find the contact information for our service centers in your region. 

There are several ways you can search for products on our website:

  • Click on the Products link in the main navigation to search by product lines.
  • Find products for a specific Industry or Application by clicking on the links in the main navigation bar at the top of the page.
  • Use our Gas Finder if you’re looking for a product that can detect a specific type of gas.
  • If you still can’t find the product you’re looking for, type the name of the product in the search bar at the top of the page.

Because we do not sell our products directly we cannot quote a specific price on our website.  Contact a sales representative through either the “HOW TO BUY” button on the product page or by calling them and they will be able to obtain pricing from local distributors in your area. 

Similar Products

Check out some of these similar products.
Control toxic or combustible gases - 301C Controller - Honeywell Analytics
Designed for simple installation and operation, the 301C continuously monitors and controls toxic gases, combustible gases and oxygen hazards.
Applications: Building ProtectionFood ProcessesParking Structures and TunnelsData CentersCommercial Kitchens
Remote annunciator panel - 301AP Annunciator Panel - Honeywell Analytics
Remote annunciator provides an efficient interface between gas transmitters and external alarming.
Applications: Building ProtectionFood ProcessesParking Structures and TunnelsCommercial Kitchens

Looking For More Information?

Check out these documents. If you can't find what you're looking for here, check out our Technical Resource library.