SP24AA — 24VAC Single-Pair Low-Voltage Surge Protector (Series / Inline) with Equipment Ground Connection
$79.00
SP24AA is a 24VAC single-pair low-voltage control circuits (HVAC, thermostats, doorbells, and fire/secuiry/alarm loops). surge protector for inline (series) installation on control and signaling circuits. Protects one circuit through Terminal A and Terminal B and uses a green equipment ground lead.
24 VAC circuits only — verify voltage before installation.
Specifications (SP24AA)
-
Device type: Low-voltage surge protective device (SPD), series / inline installation
-
Circuit pair protected: Single pair (Terminal A & Terminal B)
- Nominal operating voltage: 24 VAC
-
MCOV (Maximum Continuous Operating Voltage): 33 V
-
Clamping voltage: 39 V
-
Maximum continuous current: 5 A
-
Surge current rating: 2.5 kA
-
Protection modes: Differential (line-to-line) and Common mode (line-to-ground)
-
Terminal wire range: 30–14 AWG
-
Operating temperature: −35°C to +70°C (−31°F to +158°F)
-
Recommended spacing to protected equipment: ≥ 18 inches
-
Ground: Green lead provided; connect to equipment ground
-
Serviceability: Sealed / non-serviceable; no user-serviceable parts (do not Hi-Pot test)
The Bad Wolf SP24AA is a 24VAC single-pair low-voltage surge protector designed for inline (series) installation on control and signaling circuits. It protects one 24VAC circuit through Terminal A and Terminal B and uses the green equipment ground lead to help manage common-mode surges. SP24AA helps protect sensitive low-voltage equipment from transient overvoltage events caused by nearby lightning, utility switching, and inductive load switching.
Where it’s used
SP24AA is commonly installed on 24VAC control power and low-voltage signaling circuits, including:
-
HVAC control circuits and thermostats
-
Air handler/furnace control boards
-
Doorbell and smart doorbell transformers
-
Security/CCTV power or control loops
-
Fire/security low-voltage loops and other control wiring
- Helps protect control boards, transformers, relays, and connected low-voltage devices from transient surges.
Installation notes (important)
-
Series (inline) install required: the SP24AA is installed in line with the circuit being protected.
-
Bidirectional: either side can be used as IN/OUT.
- Maintain continuity: connect A→A and B→B through the SPD.
-
Ground connection: Connect the green ground lead to a proper equipment ground for best performance.
-
Maintain at least 18 inches between the SPD and the equipment being protected.
-
Verify the circuit is 24 VAC before installation and install per applicable electrical codes by a qualified professional.
Status and service
The SP24AA is sealed and non-serviceable. There are no user-serviceable parts. Do not Hi-Pot test the device, as this may damage the SPD.
Additional information
| Weight | 5 oz |
|---|---|
| Dimensions | 5.125 × 3.25 × 1.25 in |
| Continuous Current Rating | 5 |
| Environmental Rating | Indoor |
| Type of Electrical Current | AC |
| Voltage (Vac) | 24 |
| Application | Doorbell, HVAC, Thermostat |