b)While the tank is out, look into the lower end of the tank. Make sure the drain screen is in place. Also check for accumulations of lime at the bottom of the tank. Refer to "Steam Generator Disassembly" and "Cleaning Procedure" sections to rectify these problems.

3)If the tank drains well when the water level is high but poorly or not at all when it is low, check the duct pressure where the dispersion tube is mounted. A negative duct pressure can cause drainage problems. While this is relatively rare, it has been known to happen.

4)If the water backs up into the drain pan inside the unit, check for a blocked drain cup under the pan. If the drain cup is OK, check the drain piping for an accumulation of solids. Clean as required and increase the pitch of the drain piping if necessary. If long runs of horizontal drain pipe cannot be avoided, it may be necessary to develop some kind of drain flushing system. An air gap in between drain piping and drain hose from the EHU will allow "burping" of air from drain piping.

Fill System Failure:

Make sure the drain valve is not leaking. A leaking drain valve may appear to the humidifier as a fill system failure.

Check to see that the fill valve is operating. While the fill light is on, disconnect one of the fill valve leads (Figure 28-1, 28-2), then momentarily touch the lug to the coil terminal. You should be able to hear the valve operate.

1)If the fill light is on, but the valve is not operating, check for 24 VAC between the valve lead wires. After checking, TURN OFF THE POWER.

a)If 24 VAC WAS NOT found, check the continuity of the wires back to the circuit board. Repair broken wires as necessary. If wires are intact, call the factory for assistance.

b)If 24 VAC WAS found, disconnect the fill valve leads and check the coil resistance. It should be 18 ohms. Replace the coil if necessary.

2)If the fill valve is operating but the unit fills too slowly, check for either low water pressure (less than 25 psi) or a partially plugged screen inside the inlet fitting. If the screen tends to plug too easily, it may well be removed and replaced by a larger filter in the water line external to the unit. (NOTE: the nominal flow rate valve should be 0.31 gal/min. for each tank. The flow rate is regulated by a flow washer in the valve inlet or on the EHU-704 by flow washers in the brass tee immediately downstream of the fill valve.)

3)If the valve makes humming or buzzing noises but fails to open:

a)Check for high water pressure (over 125 psi).

b)If a backflow preventer is used, crack open a fitting between the backflow preventer and the fill valve. If this causes the fill valve to open, remove the backflow preventer from the system. Backflow preventers are not needed as the Series EHU-700 incorporates a 1 inch air gap as an anti-syphon feature.

For additional information on Armstrong Series EHU-700 Humidifiers, contact your Armstrong Representative and request Bulletin No. 596.

35

Page 34 Page 36
Page 35
Image 35
Armstrong World Industries EHU-704, EHU-700 Series, EHU-703, EHU-701 manual Fill System Failure
Page 34 Page 36

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.

Additionally, these ceiling panels are designed with durability in mind. Made from high-quality components, the EHU-700 Series is resistant to moisture and staining, making them suitable for spaces exposed to humidity, such as kitchens and restrooms. This resilience ensures that the panels maintain their aesthetic appeal over time, reducing maintenance costs for facility managers.

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.

Another significant aspect of the EHU-700 Series is its commitment to sustainability. Armstrong World Industries emphasizes eco-friendly manufacturing processes and materials, allowing architects and builders to achieve green building certifications, such as LEED. The use of recyclable materials in the panel composition reflects a commitment to reducing the environmental footprint.

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.
Top Page Image Contents