IC693CMM301通用电气
将操作控制器周围的空气保持在50°C（122°F）以下。定期检查空气温度，以：确保未超过此规格。
注意安全超过规定的工作温度限制可能会产生不利影响并可能导致控制器损坏。
当控制器安装在部分或完全封闭的面板中时，建议使用强制空气通风，或机柜（如NEMA 1）；如右图所示。当存在清洁空气时，排气扇通常安装在顶部以及形成在面板底部的百叶窗。然后，空气在站壳之间向上吸入。当空气含有颗粒物，风扇和过滤器通常位于面板底部，百叶窗位于顶部。过滤现在，空气被迫在站壳之间向上流动。过滤器必须定期维修。只能使用高质量、安静运行的风扇。
此外，风扇不应产生电噪声这可能干扰电子仪器。
密封柜（如NEMA 12或4X），包含：不产生显著热量的设备
应包含用于强制空气流动的再循环风扇
设备周围和整个机柜防止热点发展。
强制通风在非常高的密度下可能需要调节面板或控制台。定期更换或清洁空气过滤器。
污染物控制器外壳开槽，以允许清洁冷却空气。液体和腐蚀性气体必须：不允许进入案件。是否控制器位于控制室或现场安装。它必须：防止雨水、空调冷凝物，
以及与设备和工艺相关的流体和气体。长时间接触污染物可能导致：故障。
工业环境通常含有空气污染物颗粒污染物。颗粒物，通常灰尘和污垢，具有研磨性，可导致间歇性连接。电路板上的一层灰尘会干扰部件散热，并可能吸收其他空气污染物。扩展
暴露于这些污染物可能导致：故障。
尽管353块板具有保护涂层，但以下步骤可以减少与污染相关的
设备故障：风机数量：每16个站一台或面板宽度3英尺。
进气口：每个风扇30 in²。如果使用过滤器，则必须定期更换（将入口增加至50 in²）。
Keep the air surrounding an operating controller below 50°C (122°F). Check air temperature periodically to
ensure that this specification is not being exceeded.
CAUTION
Exceeding the specified operating temperature limits can adversely affect
performance and may cause damage to the controller.
Forced air ventilation is recommended when controllers are mounted in a partially or completely enclosed panel or
cabinet (e.g. NEMA 1); as shown at right. When clean air is present, exhaust fans are often mounted across the top
of a panel and louvers formed in the panel bottom. Air is then drawn upward between the station cases. When air
contains particulate matter, fans and filters are generally located at the panel bottom and louvers at the top. Filtered
air is now forced upward between the station cases. Filters must be serviced periodically.
Only high quality, quiet running fans should be used.
Also, the fans should not generate electrical noise
which could interfere with electronic instruments.
A sealed cabinet (e.g. NEMA 12 or 4X) containing
equipment that does not generate significant heat
should contain a recirculating fan for forcing air flow
around equipment and throughout the cabinet
preventing hot spots from developing. Forced air
conditioning may be required in very high density
panels or consoles. Periodically change or clean air
filters.
CONTAMINANTS
The controller case is slotted to permit circulation of
clean cooling air. Liquids and corrosive gases must
not be allowed to enter the case. Whether the
controller is in a control room or field mounted it must
be protected from rain, air conditioning condensate,
and plant and process related fluids and gases.
Extended exposure to contaminants can result in
malfunctions.
Industrial environments often contain airborne
particulate contaminants. Particulate matter, usually
dust and dirt, is abrasive and can cause intermittent
connections. A layer of dust on circuit boards can
interfere with component heat dissipation and can
absorb other airborne contaminants. Extended
exposure to these contaminants may result in
malfunctions.
Although 353 boards have a protective coating, the
following steps can reduce contaminant related
equipment malfunctions: No. of Fans: One for each 16 stations or 3 ft. of panel width.
Air Inlet: 30 in² for each fan. If filters are used, they must
be changed periodically (increase inlet to 50 in²).
