The Leviton R2120-B is a compact Type 1 SPD for 120/240 V split-phase residential systems. Its strongest documented features are a 200 kA short-circuit current rating, NEMA 4X enclosure, clear current manufacturer specifications, and a Type 1 application. Its defining tradeoff is equally clear: Leviton lists reduced protection modes, L1-N and L2-N, rather than all-mode protection.
That does not make the product categorically good or bad. It makes mode coverage a deliberate application decision. This review is based on documentation, not hands-on surge testing.
Affiliate disclosure: Surge Protection Experts may eventually earn compensation from qualifying purchases. No affiliate link is active in this draft. The product link goes to Leviton for verification, and the conclusion is based on fit and published limitations.
R2120-B specifications
| Field | Current Leviton product page |
|---|---|
| SPD type | Type 1 |
| System | 120/240 V AC split phase |
| Nominal discharge current (In) | 10 kA |
| Maximum surge current | 36 kA per mode / 36 kA per phase |
| VPR | 700 V L-N; 1,200 V L-L |
| MCOV | 180 V L-N / 360 V L-L shown in summary |
| SCCR | 200 kA |
| Protection modes | Reduced mode: L1-N, L2-N |
| Enclosure | NEMA 4X polycarbonate |
| Status | LED; no remote monitoring, alarm, counter, or replaceable modules |
| Warranty headline | $25,000 connected-equipment warranty; full terms control |
Verify the current Leviton R2120-B page, instruction sheet, specification sheet, and warranty before selection.
What the R2120-B does well
High published SCCR
Leviton publishes 200 kA SCCR, materially higher than the public values for some compact residential alternatives. SCCR concerns fault-current application; it is not the same as the unit’s 36 kA surge-current rating.
Type 1 classification
Type 1 marking allows the listed Type 1 application range, while exact placement still follows the instructions and equipment. This can make it relevant where a Type 2-only product is not the desired application.
NEMA 4X enclosure
The polycarbonate NEMA 4X enclosure supports indoor/outdoor planning and adds corrosion-resistance criteria. The final installed arrangement and entry still need to preserve suitability.
Clear documentation
Leviton’s product page exposes voltage, In, SCCR, modes, VPR, MCOV, enclosure, monitoring, dimensions, recommended breaker rating, and current UL edition in one place. That transparency makes it easier to identify tradeoffs rather than fill gaps with retailer claims.
The reduced-mode decision
Leviton lists L1-N and L2-N protection modes. In a 120/240 V split-phase system, those are the two line-to-neutral paths. The product page does not list L-G or N-G protection modes.
Do not infer that reduced-mode protection is universally insufficient or equivalent to all-mode protection. Ask the electrician to evaluate:
- the system configuration and bonding point;
- proposed device location;
- what other SPDs or protected paths exist;
- the manufacturer’s intended application; and
- whether all-mode protection is a project requirement.
The important editorial point is disclosure: buyers should not discover the mode difference after purchase.
Other tradeoffs
10 kA nominal discharge current
The R2120-B publishes 10 kA In. Current Eaton CHSPT2ULTRA and Siemens FSPD140 alternatives publish 20 kA, although those products differ in type, modes, SCCR, enclosure, and monitoring.
Basic monitoring
The product has LED status but no remote contact, audible alarm, surge counter, filtering, disconnect switch, or replaceable module. A simple design can be appropriate when the indicator is visible and routinely checked; it is less attractive where active alerting is important.
Lower surge-current headline
Leviton publishes 36 kA per mode/phase, lower than the 80–140 kA headlines on several alternatives. That single field should not override its 200 kA SCCR, VPR, modes, placement, or installation, but buyers prioritizing higher published surge-current capacity will compare other models.
Warranty headline is smaller
Leviton advertises a $25,000 connected-equipment warranty for the R Series. Read the full definitions and conditions. A smaller or larger limit is not a protection-performance rating and does not predict claim approval.
Who should shortlist it?
Consider the R2120-B when:
- the home has the documented 120/240 V split-phase system;
- a Type 1 compact external SPD fits the plan;
- 200 kA SCCR is valuable for the application;
- NEMA 4X construction suits the environment;
- L1-N and L2-N reduced-mode protection is specifically accepted; and
- visible LED-only monitoring is sufficient.
Who should compare another model?
Look elsewhere when all-mode protection, 20 kA In, audible/remote monitoring, replaceable modules, or a higher surge-current figure is a stated requirement.
- Square D HEPD80: Type 1, NEMA 4X, four VPR modes, 10 kA In, 25 kA SCCR.
- Siemens FSPD140: Type 2, all modes, 20 kA In, 200 kA SCCR, audible alarm and ground-reference monitoring.
- Eaton CHSPT2ULTRA: Type 2, four modes, 20 kA In, NEMA 4, 22 kA published SCCR.
See our full comparison for like-for-like fields.
Installer questions
- Is this Type 1 device suitable for the exact proposed location?
- Does the 120/240 V split-phase marking match the system?
- Is the reduced L1-N/L2-N mode design appropriate for the protection plan?
- How should its 200 kA SCCR be evaluated at this installation?
- Can the unit be mounted with a short, compliant path and visible LED?
- Does the NEMA 4X rating remain suitable after installation?
- What warranty registration, seller, and documentation conditions apply?
Maintenance and ownership
Check the external LED as Leviton instructs and after a known electrical event. Do not open the panel or device to diagnose an indicator. Because there is no audible or remote alert, the inspection habit is part of ownership.
Keep the invoice, product/instruction versions, installed photo, permit record where applicable, and warranty terms. If the LED changes or the enclosure is damaged, follow Leviton guidance and contact a qualified electrician.
Verdict
The R2120-B is a transparent, compact Type 1 option with an unusually high published SCCR and NEMA 4X enclosure. Its reduced L1-N/L2-N modes, 10 kA In, 36 kA surge-current rating, and basic monitoring are not footnotes—they are the selection decision. It belongs on a shortlist when those characteristics match the engineered protection path, not when a buyer assumes every Type 1 box provides the same modes.
Use how to choose a whole-house surge protector to apply the full compatibility checklist.
Sources and update policy
Reviewed October 17, 2026. Recheck current product status, exact instruction/specification sheets, and warranty immediately before publication or purchase.