Armstrong World Industries EHU-701, EHU-703 manual Operational Guidelines, Tank Contactor Operation

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A high-water float switch prevents water carry-over into the duct due to an excessive water level in the tank. When the high water limit is reached the HIGH WATER light comes on and the fill valve is blocked until some water is boiled away and the water level drops. This is common during startup. If the high water light comes on and the water level is in the lower half of the steam generator, contact the factory for assistance. This is due to high static pressure. Installation of fill cup extension kit could be required.

If an overcurrent situation is detected, the overcurrent protection circuit will drain water from the tank to reduce current flow. If the overcurrent persists, the contactor will be de-energized to stop all current flow.

The Series EHU-700 patented automatic capacity adjustment feature eliminates manual adjustment and improves humidity control. This feature automatically adjusts maximum output up or down depending on the humidity demand history. When the unit is first turned on the maximum output is 40%. If the demand stays high, the unit automatically steps up the maximum output and will reach 100% maximum output after one hour. For test purposes, or for special operating situations, this fea- ture can be easily over-ridden by changing the position of jumper BJ1 on the printed circuit board from pins 1 and 2 to pins 2 and 3.

An automatic drain cycle blows down mineral-laden water to increase steam generator life and reduce maintenance requirements. The frequency and duration of the drain cycle will vary with supply water conductivity, steam output, and humidistat demand history. When it is initiated automatically, the drain valve cycle occurs at the beginning of a fill cycle. The incoming cold water tempers the drain water to less than 160ºF after 72 hours of no demand, the unit will initiate an "End-of-Season" drain to remove stagnant water.

OPERATIONAL GUIDELINES

This section describes the conditions and indications you should expect to find in a normally operating humidifier.

Tank Contactor Operation:

The microcontroller will de-energize the contactor, turning off the current to the electrodes if ANY of the following occur:

1.The control humidistat demand signal is less tan 25%.

2.The fan interlock circuit is open.

3.The high limit humidistat circuit is open.

4.The tank current is greater than the over-current limit.

Conversely, the microcontroller will energize the contactor, turning on the current to the electrodes, only if ALL of the following occur:

1.The control humidistat demand signal is greater than 35%.

2.The fan interlock circuit is closed.

3.The high limit humidistat circuit is closed.

There is a time delay of fifteen seconds in the contactor operating circuitry to prevent it from cycling too rapidly after it has been turned off.

Monitoring Stat Demand:

Indicates the demand for humidity in relationship to the control range of the humidistat. 0% indicates that the humidity requirement has been exceeded. 100% indicates that the humidistat is calling for full humidifier output. In general, a reading of around 50% indicates that the set point has been met.

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Contents Installation and Maintenance Metal Tools Away from These Areas Table of Contents Check Local Codes PRE-INSTALLATIONCheck Shipment Site SelectionWater Total Mounting the Humidifier InstallationElectrical Service Wiring Important Please observe the followingWater Fill Supply Connect DrainPressure in duct is high, see Figure Control Wiring Control Humidistat10 Ft Wall Mounted Control HumidistatAirflow Switch Duct Mounted Control HumidistatHigh Limit Duct Humidistat Audible Alarm Generator aInstrument Panel START-UP Procedure for Armstrong Series EHU-700 Humidifiers Before Turning on the PowerTurn on Power AT the Circuit Breaker Page Page Troubleshooting Guide Operational Guidelines Tank Contactor OperationMonitoring Stat Demand Monitoring Current Monitoring % PowerManual Drain Mode Automatic Drain OperationC02 Tank Needs Cleaning EHU-700 DiagnosticsDiagnostic Display Messages C00 Normal Operation C01 High WaterC06 Fill System Failure C04 High Limit CircuitC05 Drain System Failure C07 Overcurrent FailureC09 I/O Diagnostics When Water Conductivity is TOO LOW Water Quality and Treatment for EHU Series HumidifiersGeneral Remedy When Water Conductivity is TOO HighResults RemediesSteam Generator Parts Valves and Mechanical Parts Electrical Parts EHU-700 Parts List Steam Generator Maintenance MaintenanceRecommended Maintenance Schedule To 2 Days After Start UP Month to 1 YearTank Removal and Replacement ALL Models Steam Generator Chemical Cleaning Procedure Page Tank DISASSEMBLY, CLEANING, and Electrode Replacement Models EHU-703 and 704, Single and Three PhaseModel EHU-701, Single and Three Phase Fill and Drain System RepairDrain System Failure Fill System Failure Humidistat Data Autocal ProcedureSpecifications Sensor Failure ProtectionDimensions Sensor CharacteristicsHumidity SET Point Reset by Outside Temperature AIR Supply High Limit Humidity SensorApplication Example Humidistat model number H270-69-13-10-31Dimensional Information

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.
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