Siemens NGB3K070B Molded Case Circuit Breaker
- 70A
- 3 Pole
- Bolt-On
Siemens
NGB3K070B
Molded Case Circuit Breaker
Brand
Siemens
SKU
NGB3K070B
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Siemens NGB3K070B - 70A 3 Pole Molded Case Circuit Breaker
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Description
A dependable solution for commercial power systems, the Siemens NGB3K070B is a 70A, 3-pole molded case circuit breaker. It provides essential long-time and instantaneous trip functions to maintain electrical safety. This breaker mounts into Siemens P1, P2, and P3 panelboards. When replacing this NGB frame with the newer 3VA51 series, a separate mounting strap kit is required. It features a 25kA interrupt rating at 480Y/277V, reverse feed capabilities, and an HACR rating for HVAC equipment.Specifications
| Brand | Siemens |
|---|---|
| Series | NGB |
| Amperage | 70A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC, 480Y/277VAC, 600Y/347VAC, 125/250VDC |
| Phase | 3 |
| AIC Rating | 100kA @ 240VAC, 25kA @ 480Y/277VAC, 14kA @ 600Y/347VAC, 14kA @ 125/250VDC |
| Frame Type | NGB |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1, P2, P3 Panelboards |
| Wire Gauge | 8-1/0 AWG (Cu), 8-2/0 AWG (Al) |
| Max Wire | 1/0 AWG (Cu), 2/0 AWG (Al) |
| Min Wire | 8 AWG |
| 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 |
|---|---|
| Accessories | Load Side Lugs |
| Standards | CSA C22.2 No. 5, UL 489, NEMA AB 1 |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Reverse Feed |
Product FAQs
7 answersWhich Siemens panelboards accept the NGB3K070B circuit breaker?
This bolt-on breaker is designed for use in Siemens P1, P2, and P3 commercial panelboards. It mounts directly to the panelboard bus and includes load side lugs for branch circuit wiring.
What wire sizes are accepted by the load side lugs on this 70A breaker?
The factory installed lugs accept 8 to 1/0 AWG copper wire or 8 to 2/0 AWG aluminum wire. Because the line side bolts directly to the panelboard bus, lugs are only present on the load side.
Can the NGB3K070B be used in DC electrical systems?
Yes, this breaker is rated for 125/250VDC applications with an interrupting capacity of 14kAIC, making it suitable for DC control panels and specialized industrial equipment.
What does the LI trip function indicate on this breaker?
It features a fixed thermal magnetic trip unit providing Long-Time (L) overload and Instantaneous (I) short-circuit protection. Both the thermal and magnetic trip points are factory set and non-adjustable.
Is the NGB3K070B being replaced by a newer Siemens breaker series?
Yes, Siemens is transitioning the NGB frame to the newer 3VA51 series. Installing a 3VA51 breaker into legacy P1, P2, or P3 panelboards requires a specific retrofit mounting kit. Using the NGB3K070B allows for a direct bolt-on installation in older panels without additional hardware.
Does this breaker require a separate mounting kit for installation?
When installing the NGB3K070B into original Siemens P1, P2, or P3 panelboards as a branch breaker, it bolts directly to the bus and does not require a separate mounting kit. Main or subfeed applications may require specific hardware kits like the MBKNB3.
Is the NGB3K070B suitable for reverse feed applications?
Yes, as a standard thermal magnetic breaker without specific line and load markings, it can be reverse fed for back-fed main breaker applications in compatible panelboards.
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Reviews
Review summary
Customers rate this product 4.5 out of 5 based on 8 reviews.
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Rating
8 reviews
- JHJohn H.Verified BuyerReviewingSiemens NGB3B015B - 15A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars9/16/26480v breakers
The breakers work great
- BPBland P.Verified BuyerReviewingSiemens NGB3B100 - 100A 3 Pole Molded Case Circuit BreakerI do not recommend this productRated 1 out of 5 stars7/22/26NO LUGS!!
I ordered this breaker and it arrived with no lugs. It was advertised as new so we didn't open the box and check until the shutdown we needed it for. When we discovered the lugs were missing we sent an email requesting a set overnighted. We didn't get a response for a couple of days, at which point we had already ordered lugs from their competitor Simply Breakers. They asked for pictures and questioned weather we had ordered the correct breaker asking if we needed lugs on both sides. This is a panel breaker and their is only one configuration that I am aware of which is bolted to bus in panel and wires to the three lugs on the other side. I have never had to order lugs separately for this style of breaker. They asked for pictures of box and what was in it, of course at this point the breaker is already installed and the box is thrown away. I sent a receipt for the overnight lugs from Simply breakers and asked for whatever credit they could provide. I received crickets to date. I have never had a problem with an order in the past from super breakers, but they are to busy to even respond to my request so I will think twice before I order anything from them again. It will be my last option once all others have been exhausted. Use Simply Breakers they have better stock and service.
- PFPaul F.Verified BuyerReviewingSiemens NGB3B060B - 60A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars6/24/26Great service, quick shippin
Need I say more.I have used SB. When we need it and need it quickly Always have what I need.
- BPBJ P.Verified BuyerReviewingSiemens NGB3B020B - 20A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars5/11/26NGB3B020B
I recently purchased the NGB3B020B and I’m very satisfied with the quality and performance. The breaker feels solid and well-made, and installation was straightforward. It works exactly as expected and provides reliable protection for my electrical setup. Shipping was fast and the product arrived in excellent condition. I would definitely purchase from this seller again.
- RSRadovan S.Verified BuyerReviewingSiemens NGB3B050B - 50A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars3/9/26Absolutely amazing service.
On Time