AIR SUPPLY HIGH LIMIT HUMIDITY SENSOR

The A 17898 (H270) includes a high limit circuit. This allows the use of a second humidity in the supply air. Input signal goes to terminals #8 on the humidistat. High limit set point is preprogrammed at 85%. It can be readjusted using the A19517 service tool. If you don’t use the high limit feature, connect a 1 MegΩ, ¼ watt resistor between terminals 8 and 10 (supplied with the humidistat).

Remember: this high limit function is not a safety device. For critical situations, provide installation with normal protections required to ensure a safe operation.

Table 4: Example showing proportional high limit override signal in supply duct.

Level

00%

 

Output

50%

Control

0%

 

85%

Supply Humidity

HUMIDITY SET POINT RESET BY OUTSIDE TEMPERATURE

 

The A17898 (H270) humidistat has an optional

Figure 38-1

 

outdoor temperature sensor. This sensor is used

 

 

 

TemperatureAir

32˚F

HT=32˚F

to reset the humidity set point during the cold season

to minimize condensation on windows and building

14˚F

 

structures.

 

-4˚F

 

 

 

 

When the outdoor temperature falls below the

Outside

-20˚F

LT= -20˚F

the example Figure 41-2), the humidity set point will

 

rE=20%

selected high temperature, parameter HT (32°F in

 

-40˚F

User

 

 

Setpoint

start to decrease. The lowest humidity set point will

 

 

 

be reached at selected low temperature, parameter

 

 

 

LT (-20°F).

 

 

20% 25% 30% 35% 40% 45%

 

 

 

%RH

The set point decrease from original set point down to

the lowest set point determined by the parameter rE. In the example, Figure 41-2, rE was set to 20%, therefore the humidity set point dropped from 45% to 20%.

If you don’t use the outdoor reset feature, put a jumper between terminals 6 and 9 (supplied with the humidistat).

38

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Image 38
Armstrong World Industries EHU-701 AIR Supply High Limit Humidity Sensor, Humidity SET Point Reset by Outside Temperature
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EHU-701, EHU-700 Series, EHU-704, EHU-703 specifications

Armstrong World Industries has long been a leader in the ceiling and wall solutions industry, and its EHU-700 Series exemplifies the commitment to innovation and quality. The EHU-700 Series, which includes models such as the EHU-703, EHU-704, and EHU-701, is designed for a variety of commercial applications, combining aesthetic appeal with superior performance characteristics.

One of the key features of the EHU-700 Series is its exceptional acoustic control. The panels are crafted using advanced sound-absorbing materials that effectively reduce noise levels in busy environments. This makes them ideal for areas such as offices, schools, and healthcare facilities, where quietness can significantly enhance productivity and comfort. The EHU-700 Series has been rigorously tested and certified to meet stringent industry standards, ensuring its effectiveness in noise reduction.

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The EHU-700 Series also incorporates Armstrong's innovative technologies to enhance ease of installation and flexibility. The panels feature a lightweight design, allowing for straightforward handling and installation. Compatibility with various grid systems ensures that the EHU-700 Series can be easily integrated into existing architectural designs, providing a seamless finish.

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In summary, the EHU-700 Series, including the EHU-703, EHU-704, and EHU-701 models, showcases Armstrong World Industries' dedication to quality and innovation. With unparalleled acoustic performance, durability, installation convenience, and sustainability, these ceiling panels are ideal for a wide array of commercial environments, proving to be a valuable investment for modern architectural needs. Their combination of functionality and design ensures that they meet the demands of today's dynamic spaces.
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