Viconics H270 - Manual

1
ELECTRONIC HUMIDISTAT: H270
• ONE OR TWO STAGES
• HUMIDITY SUPPLY HIGH LIMIT
• OUTDOOR TEMPERATURE RESET
DESCRIPTION
The H270 series low voltage, microcomputer-based PI
(proportional and integral) humidistats are designed for
accurate humidification and/or dehumidification control
in commercial applications such as: hospitals, schools,
office buildings, retail stores, museums, computer
rooms, etc.
The H270 series is available with one or two outputs
for maximum flexibility. Outputs can be of the following
type: proportional, on/off, and pulse width modulation
(PWM). Two additional inputs are provided in order to
perform unique functions: humidity setpoint reset
based on outdoor air temperature and proportional
high limit override. The former function minimizes
condensation on window surfaces during cold outdoor
temperatures by automatically lowering the humidity
setpoint as the outdoor temperature drops. The latter
function improves accuracy and safety by throttling
back the humidifier control output if the humidity level
reaches unacceptably high levels.
There are many different types of mounting
configurations available. Sensing options include
remote duct and room as well as integral room and
duct. Setpoint adjustment can be either concealed or
exposed, adding even more versatility to the product.
Exposed models feature internally selectable minimum
and maximum setpoint knob stops.
In order to facilitate periodic recalibration, the H270
series contains a unique autocal key, which permits instant recalibration (see dimension drawing on page 5
for location).
Each humidistat is computer calibrated and factory
programmed with default parameters. All control
parameters (such as proportional band, stage
differential, etc.) may be changed in the field with the
H263 programming tool without having to remove the
thermostat cover. The H263 also doubles as a
diagnostic tool and indicates the status of all the inputs
and outputs, and will reduce troubleshooting time by
quickly identifying the specific problem.
Fig.1 Wall mounted humidistat
Features Benefits
• Microcomputer-based design with PI algorithm ⇒ Exceptional accuracy
• One or two outputs ⇒ Controls humidification and dehumidification equipment
• On/off and/or proportional outputs ⇒ Greater flexibility
• Direct or reverse acting outputs ⇒ Controls humidification and dehumidification equipment
• Integrated and remote sensing ⇒ Larger choice of mounting options
• Autocal button ⇒ Permits instant recalibration
• Concealed or exposed set point ⇒ Can be used in a large variety of environments
• Ouput signal to digital indicating devices ⇒ Increases functionality of product
• Optional H263 diagnostic tool with digital display ⇒ Simplifies troubleshooting
• Sensor failure protection ⇒ Prevent water dammage
• Humidity setpoint reset based on outdoor temp. ⇒ Prevents window condensation in colder climates
• Proportional high limit override ⇒ Prevents costly damage due to over-humidification
• CE approved ⇒ Can be sold in European markets