Recommendations for Sealed Systems Z23x
1. Follow vendor recommendations for minimum clearances around active equipment (e.g. typically 2" for convection
cooled switches).
2. Mount equipment with lower recommended operating temperatures on the lower DIN rails.
3. When possible stagger switches to avoid placing a switch directly below another switch as the lower switch can
increase the air temperature significantly for the upper switch.
4. Figure 3 provides a guide for a sealed Panduit Z23 enclosure heat dissipation for various external ambient temperatures
5. For outdoor deployments a 150-watt heater will increase the internal temperature of a sealed Panduit Z23 enclosure by
15°C above the external ambient temperature.
Figure 3: Z23 Enclosure Thermal Guideline – Sealed
Example 1: Determine the heat load allowable for an 85°F ambient temperature and an internal enclosure temperature of 113°F.
Answer: The maximum allowable power draw for the equipment inside the enclosure is 162 watts.
How to: Find the 85°F point on the bottom horizontal axis. From that point draw a vertical line to the sloped 113°F internal air
temperature line. Then draw a horizontal line to the right hand vertical axis.
Example 2: Determine the size of a heater required to maintain an internal temperature of 15°C when the enclosure is exposed to a
-15°C outside ambient temperature and the power draw of the active equipment inside the enclosure is 150 watts. The enclosure is
not exposed to direct sunlight.
Answer: A single 150-watt heater is needed to maintain the internal temperature at 15°C.
How to: Apply recommendation #5 to the problem. The Z23 enclosure internal temperature will be 15°C greater than the ambient
temperature for every 150-watts of heat dissipation. The power draw of the active equipment plus the heater 150w + 150w = 300w = a
30°C temperature increase so -15°C (ambient) + 30°C (from the total heat load) = 15°C inside the enclosure.
4
