GE VersaMax Manual page 477

A
Thermal Considerations
The thermal performance specified for modules in this manual requires a clearance
of 2 inches (5.1cm) above and below the modules and 1 inch (2.54cm) on each side
of the modules as shown below, regardless of the orientation of the DIN rail.
2.54cm
(1.0in)
Mounting Modules on a Vertical DIN Rail
When using a vertical DIN rail, the CPU or NIU module must be installed at the
bottom.
Some VersaMax I/O modules require thermal derating. The "Thermal Derating"
section of these modules' descriptions provides specific derating information. In
general, mounting a module on a vertical DIN rail increases the ambient temperature
around each module, due to the cumulative effect of the rising heat. Therefore,
modules that have a thermal derating when mounted on a horizontal DIN rail will
have a greater derating when mounted on a vertical DIN rail
Modules that do not have a thermal derating when mounted on a horizontal DIN rail
also have no derating when installed on a vertical DIN rail.
A-2 VersaMax® Modules, Power Supplies, and Carriers User's Manual – March 2003
5.1cm
(2.0in)
5.1cm
(2.0in)
5.1cm
(2.0in)
CPU or NIU
at Bottom
2.54cm
(1.0in)
2.54cm
(1.0in)
2.54cm
(1.0in)
GFK-1504K
5.1cm
(2.0in)