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Siemens HED42B125L Molded Case Circuit Breaker
- 125A
- 2 Pole
- Unit Mount
Siemens
HED42B125L
Molded Case Circuit Breaker
Brand
Siemens
SKU
HED42B125L
Quantity
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Siemens HED42B125L - 125A 2 Pole Molded Case Circuit Breaker
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Description
Designed for standalone applications, this 125A thermal-magnetic breaker provides reliable LI protection. The unit achieves a high interrupting rating of 42kAIC at 480VAC. Unlike bolt-on variants, this unit-mount model includes both line and load lugs. It installs easily into individual enclosures, switchboards, or motor control centers. The non-interchangeable trip mechanism ensures consistent performance. It is fully HACR rated and supports reverse feeding for flexible routing.Specifications
| Brand | Siemens |
|---|---|
| Part Number | HED42B125L |
| Series | HED4 |
| Amperage | 125A |
| Poles | 2 |
| Mounting Style | Unit Mount |
| Voltage | 240VAC, 480VAC, 250VDC |
| Phase | 1 |
| AIC Rating | 100kA @ 240VAC, 42kA @ 480VAC, 30kA @ 250VDC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Enclosures, Switchboards, Motor Control Centers |
| Wire Gauge | 3 AWG - 3/0 AWG (Cu), 1 AWG - 2/0 AWG (Al) |
| Max Wire | 3/0 AWG (Cu), 2/0 AWG (Al) |
| Min Wire | 3 AWG (Cu), 1 AWG (Al) |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Fixed Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Undervoltage Release |
|---|---|
| Accessories | Line and Load Lugs Included |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489 |
| Approval | CSA, HACR, IEC, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Current Limiting, Reverse Feed, Non-Interchangeable Trip |
Product FAQs
6 answersWhat enclosures are compatible with the HED42B125L circuit breaker?
This ED-frame breaker mounts in Siemens Sentron switchboards, motor control centers, and individual enclosures such as the E2N1S (surface mount NEMA 1), E2N1F (flush mount NEMA 1), and E2N3R (NEMA 3R).
What does the "L" suffix in the HED42B125L catalog number indicate?
The "L" suffix indicates that the breaker is factory-supplied with both line and load side lugs. Standard ED-frame breakers without the suffix typically include load side lugs only.
What is the difference between Siemens HED4 and ED4 circuit breakers?
The primary difference is the interrupting rating. The HED4 series is rated for 42kAIC at 480VAC, while the standard ED4 series is rated for 18kAIC at 480VAC. Both share the same physical ED frame footprint.
Can the Siemens HED42B125L be reverse fed?
Yes. Because this breaker features a non-interchangeable thermal-magnetic trip unit, it is suitable for reverse feeding applications according to UL 489 standards.
Which replacement lug kits fit this 125A ED-frame breaker?
Compatible lug kits include the TA1E6125 (standard aluminum body for copper or aluminum wire), TC1ED6150 (copper body for copper wire only), and the CCE125 compression lug kit.
Can I install the HED42B125L in a standard residential load center?
No. This is a unit-mount molded case circuit breaker designed for industrial control panels, switchboards, and enclosed disconnects. It does not plug or bolt into standard residential load centers.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 13 reviews.
Total 5 star reviews: 13 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
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Rating
13 reviews
- PMPete M.Verified BuyerReviewingSiemens HED43B060 - 60A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars8/19/26Good price - Best website
Awesome price on an item. easy to use website made finding the right breaker and purchasing it super easy
- BCBrad C.Verified BuyerReviewingSiemens HED43B070 - 70A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars5/12/26Thank You
The breaker works perfectly, but I'm more impressed by the fast, prompt delivery. Will be using you again, thank you.
- MLMichael L.Verified BuyerReviewingSiemens HED43B020 - 20A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars4/15/26Siemens breaker
Return customer, always great service and quick delivery. A+++
- JMJonathan M.Verified BuyerReviewingSiemens HED43B030 - 30A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars2/10/26Breaker
Fast Delivery, just what I ordered !!
- RFRussell F.Verified BuyerReviewingSiemens HED41B040 - 40A 1 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars2/6/26Just what I ordered
Straight forward, simple process. On time delivery.