MS4PMUHVT Multi-Stage Electronic Temperature Control with ...

FCC Compliance Statement
This equipment has been tested and found to
comply with the limits for a Class A digital device
pursuant to Part 15 of the FCC Rules. These limits
are designed to provide reasonable protection
against harmful interference when the equipment is
operated in a commercial environment. This
equipment generates, uses, and can radiate radio
frequency energy and, if not installed and used in
accordance with the instruction manual, may cause
harmful interference to radio communications.
Operation of this equipment in a residential area is
likely to cause harmful interference, in which case
the user will be required to correct the interference
at his/her own expense.
Canadian Compliance Statement
This digital apparatus does not exceed the Class A
limits for radio noise emissions from digital
apparatus set out in the Radio Interference
Regulations of the Canadian Department of
Communications.
Application
IMPORTANT: The MS4PMUHVT Multi-Stage
Temperature Control is intended to control
equipment under normal operating conditions.
Where failure or malfunction of the MS4PMUHVT
control could lead to an abnormal operating
condition that could cause personal injury or
damage to the equipment or other property, other
devices (limit or safety controls) or systems (alarm
or supervisory systems) intended to warn of, or
protect against, failure or malfunction of the
MS4PMUHVT control must be incorporated into
and maintained as part of the control system.
The MS4PMUHVT control provides direct control in
many applications:
• cooling tower pump and/or fan control
• rooftop heating or cooling units
• boiler or pump control
• space temperature control
• compressor or chiller staging
The MS4PMUHVT control has four heavy-duty
relays. See electrical ratings in Table 6 for more
information.
Operation
Mode Selection
Mode Selection allows selection of one of several
modes:
• Direct mode for cooling applications
• Reverse mode for heating applications
• Deadband mode for applications requiring cooling
and heating with a common setpoint and a
deadband
• Independent Setpoint mode for applications
requiring cooling and heating with one setpoint for
heating and a second (independent) setpoint for
cooling
Stage Control
Several settings define the control functions for the
stages:
• Setpoints and Differentials setting establish the
temperature-control ranges.
• Cycle Delays establish a set time interval between
heating or cooling cycle restarts to avoid excessive
cycling.
• Soft Start controls the rate at which temperature
approaches the Setpoint on power-up or when
Binary Input Option 3 is selected. This feature is
useful when starting equipment where merchandise
in the controlled space needs to be slowly brought to
the desired temperature (Setpoint). If this feature is
used, the control activates up to four stages in
succession to slowly bring the sensed temperature
to the desired temperature (Setpoint) at the
user-selected rate.
Alarm Management
Several settings define the control functions for alarms:
• High and Low Temperature Alarms provide
notification of temperatures that exceed
user-designated high and low limits.
• Alarm Time Delay keeps short-duration
temperature changes from triggering an alarm.
• Alarm Differential keeps the alarm from cycling
rapidly on and off due to minor temperature
fluctuations.
• Alarm Codes assist in troubleshooting.
2 MS4PMUHVT Multi-Stage Electronic Temperature Control with Relay Pack Product/Technical Bulletin