Bussmann TB300-03 Double Row B...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$58.73
$10.03
Bussmann TB300-03 Double Row Terminal Block

Bussmann TB300-03 Double Row Barrier Terminal Block, 3-Pole, 30A

(No reviews yet) Write a Review

Model: TB300-03
Selected Model is

In Stock (leaves warehouse same day if ordered before 3pm ET)

$58.73
$10.03
Adding to cart… The item has been added
Free Shipping on orders over $199
We price match and offer bulk discounts! Click Add to Quote. It's quick and easy.
✨
Earn points with this purchase! You can redeem points for giftcards, iPads, XBox's and more. View Rewards
Free Keying on all locks
You may also like

Bussmann TB300-03 Double Row Barrier Terminal Block, 3-Pole, 30A

The Bussmann TB300-03 Double Row Barrier Terminal Block is a three-pole terminal block rated 30A at 600V, engineered with tin-plated brass terminals and zinc-plated steel philslot screws for dependable low- and mid-voltage wiring connections. It features #8-32 TPI screw terminals with a 16 lb-in torque rating, an operating temperature range of -40° to 130°C, and a 7500V breakdown voltage rating, making it well suited to industrial control panels, machine wiring, and OEM equipment assemblies.

Key Features

  • Amperage Rating: 30A for reliable power and control circuit connections.
  • Voltage Rating: 600V for use in higher-voltage industrial applications.
  • Three-Pole, Double Row Configuration: Barrier-style double row construction accommodates three-pole wiring in a single compact block.
  • Connection: #8-32 TPI screw terminals with a 16 lb-in torque rating for secure, vibration-resistant connections.
  • Durable Construction: Tin-plated brass terminals and zinc-plated steel philslot screws provide corrosion resistance and long service life.
  • Operating Temperature: Rated from -40° to 130°C for use across a wide range of industrial environments.
  • Breakdown Voltage: 7500V breakdown voltage rating adds dielectric insulation strength.
  • Finish: Black terminal block body.

Technical Specifications

  • Amperage Rating: 30A
  • Connection: #8-32 TPI Screw
  • Number Of Poles: Three-pole
  • Operating Temperature: -40° to 130°C
  • Special Features: Breakdown voltage 7500V
  • Torque Rating: 16 lb-in
  • Voltage Rating: 600V
  • Product Type: Double row, barrier
  • Product Length: 10.2 IN
  • Product Details: Double row, barrier
  • Product Color: Black
  • Mounting Method: Screw
  • Product Height: 3.7 IN
  • Product Material: Tin-plated brass terminal, Zinc-plated Steel philslot screw
  • Product Weight: .116 LB
  • Product Width: 8.9 IN

Typical Applications

  • Industrial Control Panels
  • Machine and Equipment Wiring
  • Power Distribution Assemblies
  • OEM Electrical Equipment
  • Terminal Wiring for Motor Control Circuits

Why Bussmann?

Bussmann is a trusted name in electrical connection and protection products, and the TB300-03 terminal block reflects that reputation with tin-plated brass terminals and zinc-plated steel screws built for durable, corrosion-resistant connections in demanding industrial settings. With a wide -40° to 130°C operating range and a 7500V breakdown voltage rating, this double row barrier terminal block delivers dependable performance for electrical professionals building code-compliant control and power distribution systems.

Manufacturer Resources

Product Specs

Amperage Rating:
30A
Connection:
#8-32 TPI Screw
Number Of Poles:
Three-pole
Operating Temperature:
-40° to 130°C
Special Features:
Breakdown voltage 7500V
Torque Rating:
16 lb-in
Voltage Rating:
600V
Product Group:
0
Department:
Electrical
Product Subgroup:
0
Product Type:
Double row, barrier
Product Length:
10.2 IN
Product Details:
Double row, barrier
Product Color:
Black
Mounting Method:
Screw
Product Height:
3.7 IN
Product Material:
Tin-plated brass terminal, Zinc-plated Steel philslot screw
Product Weight:
.116 LB
Product Width:
8.9 IN

Bussmann TB300-03 – Frequently Asked Questions

1) Can the Bussmann TB300-03 terminal block handle a 480V three-phase control circuit?
Yes. The TB300-03 is rated 600V, so a 480V three-phase feed is inside its rating, and with three poles you land each phase on its own circuit. Current is capped at 30A per pole. The block also carries a 7500V breakdown voltage rating for dielectric strength against transients.
2) What torque should I use on the TB300-03 terminal screws, and what size are they?
The screws are #8-32 TPI, torqued to 16 lb-in. Use an inch-pound torque screwdriver rather than guessing by feel. The screws are philslot zinc-plated steel, so a Phillips or a flat blade both drive them. Re-torquing after the first thermal cycle is normal practice on barrier blocks.
3) How does the TB300-03 mount, and will it fit on DIN rail?
It is a screw-mount barrier block, not a DIN rail component. You fasten it to the panel subplate or enclosure backplate through its mounting holes. If your panel is laid out on 35mm DIN rail, you either need a DIN-mount block instead or a rail-mounted adapter plate to carry this one.
4) Will this terminal block survive an unheated outdoor equipment enclosure?
Its operating range is -40 to 130 degrees C, which covers unheated winter enclosures and hot machine cabinets alike. The terminals are tin-plated brass and the screws zinc-plated steel, both plated for corrosion resistance. The block itself is not an enclosure, so the surrounding cabinet still has to keep moisture off it.
5) What is the difference between a double row barrier block like this and a single row block?
A double row barrier block puts terminals on both sides of each pole, so an incoming conductor lands opposite its outgoing conductor and the barrier wall between poles keeps strands and spade lugs from bridging. The TB300-03 does that for three poles in one piece. A single row block gives you one landing per position and needs jumpers or a second block to make a through connection, which is why double row is the usual choice for feed-through wiring in control panels.
6) Can I land ring or spade lugs on the TB300-03?
Yes, that is the normal termination for this style. The #8-32 screw terminals accept a crimped ring or spade terminal sized for a #8 stud, tightened to 16 lb-in. Ring terminals are the better choice under vibration because they cannot back out if a screw loosens.
7) Is the TB300-03 suitable for a motor starter circuit pulling more than 30 amps?
No. Thirty amps is the ceiling per pole, so a motor circuit drawing above that needs a higher-rated block. Match the block to the conductor ampacity and overcurrent device, not to nameplate FLA alone. For circuits at or below 30A and 600V, including three-phase motor control wiring, the TB300-03 is within rating.
8) What is the exact Bussmann part number for this 3-pole 30A barrier block?
TB300-03 is the Bussmann manufacturer part number. It identifies the three-pole version of the TB300 barrier block family rated 30A at 600V, in black.
How fast can I get the Bussmann TB300-03 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Bussmann TB300-03 come with a warranty?
Absolutely. The Bussmann TB300-03 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Bussmann TB300-03?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Bussmann TB300-03 from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support, and rewards on every order. Our team is always ready to help you choose the right product for your project.
!