solid state relays ssr relay

din rail heat sink

As your ambient temperature increases or as your amperage increases, the use of a properly sized heatsink is necessary. Hint: the smaller the "heat sink rating" number, the better the heatsink is at capturing and dissipating the heat. The Power-io heatsinks are the outstanding choice for most applications because they:

  • use the least amount of sub-plate mounting space,
  • extend the heat sink forward for the best air flow, optimized thermal dissipation flow channels, and surface area exposure
  • occupy about the same side-to-side physical space as mercury or mechanical contactors so new or retrofit installations are easy
  • use an universal mounting bracket -- they can be din rail mounted for fast installations without the need for drilling and tapping pre-aligned hole patterns or they can be attached with a standard bolt.

Please note: our documented DIN heat ratings are based upon the conservative estimate of being installed in "still air and clipped onto a din rail". Your actual performance will be better than our ratings if: 1) the DIN heatsinks are screwed to a metal subplate (which provides additional heatsinking capability) and/or 2) if there is any airflow in your installation, such as fan cooling. You must use a thermal conduction grease (such as Dow Corning 340™) or a Power-io Thermal Pad in order to achieve the proper heat sinking capability between the SSR and the heatsinks shown below.

Hint: Solid state relays are semiconductor devices that generate heat in proportion to the quantity of amps being switched. Heat sinks capture that thermal rise and dissipate it. Heat sinks are rated by a ºC/W number that represents: for every watt of heat generated, the solid state relay will increase by xºC. For example: if you put 30 watts of heat on a 2ºC/W heat sink, the solid state relay's internal SCR dies will rise 60ºC (30 x 2ºC) above the ambient temperature. Therefore, the lower the °C/W rating, the more aggressively the heat sink captures and dissipates the heat. See our Power-IO data bulletins (AC switching SSR) or (DC switching SSR) for thermal charts for your particular application. It is important that you use a properly sized heat sink or else the SSR product will be permanently damaged.

din rail solid state relay ssr contactor

HEATSK-DIN-1.6

Perfect size -- smallest outside dimensions while providing optimized heatsink capability. Uses about the same panel space as the just the SSR while providing the proper heatsink capability that is required for the majority of "typical" 5 - 40 amp applications.

  • Width: 2.36 inches  Height: 3.4  Depth: 2.8
  • Two 8-32 tapped holes for relay mounting
  • Attaches to a standard 35mm din rail OR it can be screw mounted to your electrical enclosure.
  • Heat dissipation rating: 1.6°C/W
  • Best value and smallest size for many 5-40 amp applications.
  • Heat sink dimensions -- drawing
  • Data bulletin
  • Buy
din rail solid state relay ssr contactor

HEATSK-DIN-1.0

Compact size -- small width dimensions while providing optimized heatsink capability. An engineering-optimized design uses the minimum amount of installation space while providing the proper heatsink capability that is required for the majority of "typical" 25 - 60 amp applications.

  • Width: 2.36 inches  Height: 4.83  Depth: 3.4
  • Two 8-32 tapped holes for relay mounting
  • Clips to a 35mm din rail OR it can be screw mounted to your electrical enclosure (four 0.187 mounting holes)
  • Heat dissipation rating: 1.0°C/W
  • Performance engineered for thermal efficiency = best value and smallest size for many 25-60 amp applications
  • Heat sink dimensions -- drawing
  • Data bulletin
  • Buy

heat sink

Only 3.15 inches (80mm) wide

Ultra Power Cooler™ (Trademark of POWER-IO) At 0.2°C/W, this heat sink is the work horse -- any amperage application, at almost any ambient temperature, in any high density installation!

The Ultra Power Cooler is a fan assisted heat sink design. This permits better heat dissipation, while still occupying a very small installation area. Ideal for the higher amperage SSRs, custom SSR or IGBT applications, warm ambient temperature installations, or high density installations that have restricted free air flow.

  • Width: 3.15 inches H: 6.50  D: 4.0
  • Two 8-32 tapped holes for relay mounting (order relay separately)
  • Clips to a 35mm din rail OR it can be screw mounted to your electrical enclosure (four mounting holes)
  • Heat dissipation rating: 0.2°C/W
  • Install edge-to-edge on a din rail with NO space between them.
  • Industry standard, 80mm AC Fan requires 120 VAC at 9 watts
  • Industry standard, 80mm DC Fan requires 24 VDC at 100mA
  • UPC heat sink dimensions -- drawing and photos
  • Pricing: Consult factory.

heatsinks

Ultra Power Cooler™ Install multiple solid state relays, mosfets, or Power-io IGBT modules and still have excellent cooling in a small footprint.

  • Width: 3.15 inches H: 6.50  D: 4.0
  • Four 8-32 tapped holes for twin relay mounting (order relays separately)
  • Heat dissipation rating: 0.4°C/W per relay
  • Custom lengths, custom hole patterns, just ask!
  • UPC heat sink dimensions -- drawing and photos
  • Pricing: Consult factory.
din rail solid state relay ssr contactor

HEATSK-3PK-1.2 or HEATSK-6PK-1.2
 (3 or 6 zones at 1.2 °C/W per zone)

The "6 Pack" or the "3 Pack" have a small width dimension while providing excellent heatsink capability. While only 2.4 inches wide and 22 inches high (6 Pack) or 11 inches (3 Pack), these multi-zone heat sinks can be populated with several of the "H" hockey puck relays. Ideal for: several single phase zones, three phase zones, and similar applications.

  • Width: 2.4 inches  H: 22  D: 3.4  for HEATSK-6PK-1.2
  • Width: 2.4 inches  H: 11  D: 2.8  for HEATSK-3PK-1.2
  • Twelve (or six) 8-32 tapped holes for relay mounting
  • Can be screw mounted to your electrical enclosure (0.187 mounting holes)
  • Heat dissipation rating: 1.2°C/W per location. The thermal rating is better than 1.2°C/W, if some locations are not populated.
  • Performance engineered for thermal efficiency
  • 6 pack drawing and photos
  • HEATSK-6PK-1.2 Buy
  • HEATSK-3PK-1.2 Buy

heat sink

Traditional SSR Heat Sink

The traditional heat sink designs are still available for applications where there is a very large area for the installation. The HEATSK-1.5-SM is 4.75 inches wide and 3 inches long. It is rated at 1.5ºC/W which is for typical 5-40 amp applications. The HEATSK-1.0-SM is 4.75 inches wide and 5.5 inches long. It is rated at 1.0ºC/W which is for typical 25-60 amp applications. Both heatsinks are attached by screws to the electrical cabinet.

din rail solid state relay ssr contactor

Thermal Transfer Pad

This high performance dry pad looks like a piece of black aluminum foil. It is sandwiched between the relay and the heat sink. When the relay is activated, the relay’s heat changes the dry pad into the optimal amount of thermal grease. Quick, easy, clean. Just the “right amount” to ensure the best thermal transfer characteristics. When installing the thermal pad, ensure that you fully tighten the two installation screws. Recommended torque: 20 - 25 inch pounds.

  • Buy THERMAL-PAD (1 piece)
  • Buy THERMAL-PAD-005 (5 pieces)

ssr screws

Mounting Screws (relay to heat sink)

The recommended mounting screws are two 8-32 x 3/8 long screws. We typically use phillips head screws but customers can use other screw head styles that match your local installation equipment. Our part number is: SCRW,8/32X3/8PH (pair of: screws, 8-32, 3/8 inch long, phillips head) for our standard solid state relays. For the HDD-E family, we recommend using the 1/2 long screws and the #8 size washers

  • Buy standard screw for HDA, HAA, or HDD applications.
  • Buy longer screw for HDD-xxxxE applications
  • Buy washer for HDD-xxxxE applications

mov

MOVs

A MOV adds a fourth layer of voltage surge survival to our trademarked Maximum Surge Survival™ design. The MOV is beneficial if the application is exposed to a high quantity of repetitive AC surges, or to very high amplitude AC surges. A MOV is strongly encouraged on Power-IO motor starters since a motor's coil is a large voltage surge generator (inductive flyback). By design, the Maximum Surge Survival circuit offers the first three strong layers of defense, so the MOV is considered additional protection.

  • Buy MOV for 24-265Vac loads
  • Buy MOV for 120-575Vac loads
 

Pre-installed labor

If you wish, we can pre-assemble exactly what you order. First, order your relay, MOV (if desired), and heat sink. This service is a single line item that will: add one thermal pad, add a pair of installation screws, assemble the unit, and torque the installation screws to 20-25 inch pounds. The cost is per SSR.

  • Buy


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