Free Shipping Over $99
Eaton / Cutler-Hammer CHF240ST Miniature Circuit Breaker
- 40A
- 2 Pole
- Plug-On
Eaton / Cutler-Hammer
CHF240ST
Miniature Circuit Breaker
Brand
Eaton / Cutler-Hammer
SKU
CHF240ST
Quantity
Shop with Confidence
Add an extra year of protection in your cart.
Eaton / Cutler-Hammer CHF240ST - 40A 2 Pole Miniature Circuit Breaker
New
Quantity
Similar Items
30A 2 Pole Miniature Circuit Breaker
20A 2 Pole Miniature Circuit Breaker
Description
Providing advanced control for commercial and residential systems, this 40-amp unit integrates a 120VAC shunt trip mechanism. This allows facility managers to remotely open the circuit during emergencies or specific operational sequences. It mounts into standard Eaton Type CH enclosures, occupying three 3/4-inch spaces due to the attached accessory.Specifications
| Brand | Eaton / Cutler-Hammer |
|---|---|
| Part Number | CHF240ST |
| Series | CHF |
| Amperage | 40A |
| Poles | 2 |
| Mounting Style | Plug-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Frame Type | CH |
|---|---|
| Terminal Type | Box Lugs |
| For Use With | Type CH Load Centers |
| Wire Gauge | 14-2 AWG (Cu/Al) |
| Max Wire | 2 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment |
|---|---|
| Accessories | Shunt Trip (120VAC), Trip Flag |
| Standards | HACR Rated, UL 489 |
| Approval | UL, UL 489 |
| Temp Rating | 60C to 75C |
| Construction Features | Visual Trip Indicator, HACR Rated, Common Trip |
Product FAQs
7 answersWhich load centers are compatible with the CHF240ST?
This plug-on breaker is designed exclusively for Eaton and Cutler-Hammer Type CH load centers. It features a 3/4-inch format and will not fit in Type BR or competitor panels.
How much panel space does the CHF240ST require?
The CHF240ST requires three 3/4-inch spaces in a Type CH panel. The two-pole breaker occupies two spaces, and the integrated shunt trip mechanism requires a third adjacent space.
What function does the shunt trip provide on the CHF240ST?
The factory-installed 120VAC shunt trip allows the breaker to be opened remotely. This is typically used for emergency power-off systems, fire alarms, or automated control sequences that require remote disconnection of the circuit.
How does the trip flag function on CHF series breakers?
The CHF240ST includes a mechanical trip flag that appears when the breaker trips. This visual indicator allows electricians and facility managers to quickly distinguish between a breaker that has tripped due to a fault and one that was manually switched off.
What type of trip curve does the CHF240ST utilize?
This breaker uses a fixed thermal-magnetic trip mechanism. The thermal element provides long-time delay protection against mild overloads, while the magnetic element provides instantaneous tripping during severe short-circuit conditions.
Does the CHF240ST feature a common trip mechanism?
Yes, this two-pole breaker includes an internal common trip connection. If an overcurrent or short circuit occurs on either leg, both poles will trip simultaneously to safely disconnect all power to the circuit.
What wire sizes and materials are compatible with the CHF240ST lugs?
The box lug terminals accept 14 AWG through 2 AWG wire. They are rated for use with both copper and aluminum conductors.
SuperClub
Join free. Get 500 SuperPoints.
Earn points on eligible purchases and redeem them at checkout.
100 SuperPoints = $1 off.
Warranties
Add an extra year of protection
60-Day Warranty
Your purchase includes 60 days of SuperBreakers warranty coverage.
Add a 1-year warranty extension in your cart.
Get a Quote
Don’t see what you’re looking for?
We source obsolete and hard-to-find parts every day.
Shipping
Free Shipping Policy
Parcel shipments with item value over $99 qualify for free economy shipping within the continental US. Please call to confirm special handling instructions. We do not charge a handling fee or require a minimum amount on any order. SuperBreakers does not ship on customer accounts.
Same Day Shipping
We strive to ship out your items the same day the order is placed. In rare circumstances SuperBreakers may reserve up to 5 business days to consolidate orders for complete shipment.
Expedited Shipments
Orders being shipped via Next Day Air, 2 Day Shipping or 3 Day Shipping must be received by 3 PM EST to guarantee same-day shipments. Expedited orders only ship on normal business days. Shipments will NOT be sent out on Saturdays and Sundays.
International Shipping
All International orders require a $1,000 minimum order threshold. Due to the special nature of these shipments, we require that these be placed with a SuperBreakers representative. Additional shipping and instructions will apply. All International Orders are Non-Cancel and Non-Refundable.
Reviews
Review summary
Customers rate this product 4.9 out of 5 based on 45 reviews.
Total 5 star reviews: 44 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 1
Reviews Summary
Generated by AI from 44 most recent customer reviews
Last updated 3/6/26
Customers say these breakers work perfectly and fit exactly as described. Many reviews mention the company stocks hard-to-find parts that local hardware stores don't carry. Users appreciate the competitive pricing, often noting costs are lower than big box stores. Fast shipping and delivery times consistently exceed expectations. The ordering process is described as simple and straightforward. Customers frequently mention they will use the service again and recommend it to others. One negative review cited delayed fulfillment and high return fees affecting their business operations.
Search
Rating
45 reviews
- JMjim m.Verified BuyerReviewingEaton / Cutler-Hammer CHF120ST - 20A 1 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars4/6/26Shunt trip
Perfect for the ansul hood suppression shutdown.
- CWCody W.Verified BuyerReviewingEaton / Cutler-Hammer CHF250 - 50A 2 Pole Miniature Circuit BreakerI do not recommend this productRated 1 out of 5 stars2/10/26Product is fine but customer service is not great!
I needed these breakers for an install - first time using the company. They said they had them in stock. Took over a week to fulfil the order and it was 11 or 12 days before I had my hands on them. Tough on my business. Then when I went return them they hit me with so many fees that I was gonna net under $30 on a $104 order. It's too bad this was my first experience with them. I'll be sure to tell my electricians and project managers to never use this company. Short sighted. They won the battle but lost the war with a potential great long term client.
- JOJoseph O.ReviewingEaton / Cutler-Hammer CHFCAF120 - 20A AFCI Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars10/30/22A++;
A++;
- JRJoseph R.ReviewingEaton / Cutler-Hammer CHFAFGF120 - 20A Dual Function Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/8/22Just as described
Quick turnaround, right fit
- RBRay B.ReviewingEaton / Cutler-Hammer CHFGFT120PN - 20A GFCI Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars2/24/22Great price and inventory
Looking for a hard to find part, these guys have it. Shopping was fast and easy. Part arrive faster than expected. Will be my go to for breakers!