Carrier 50HJQ004-016 Product Data page 189

DESCRIPTION DESCRIPTION
(Enviro-Shield™
Option) Non-Corrosive
Standard, Al/Cu
Pre-Coated Al/Cu
Cu/Cu
E-Coated Al/Cu
E-Coated Cu/Cu
LEGEND
Al/Cu --- Aluminum Fin with Copper Tube Coil
Cu/Cu -- Copper Fin with Copper Tube Coil
Enviro- Shield -- Family of Coil Protection Options
E- -Coated -- Extremely Flexible and Durable Epoxy Coating Uniformly Applied to the Coil Surfaces
Pre- -Coated -- Epoxy Coating Applied to Fin Stock Material
*See "Selection Guide: Environmental Corrosion Protection" Catalog No. 811-217 for more information
EconoMi$er IV
The EconoMi$er IV factory-installed economizer package includes a
gear-driven damper system that modulates the return air and outdoor
air supply to the rooftop unit in order to take advantage of "free
cooling" with outdoor air when conditions are suitable. The system
utilizes industry proven technology available for integrating the use
of outdoor air for cooling with mechanical cooling for 3 through
15-ton rooftop units. The intuitive EconoMi$er IV solid-state
controller optimizes and enhances rooftop operation through reduced
energy consumption, optimal zone comfort, and efficient equipment
cycling. This is accomplished by operating the compressors when
the outdoor air temperature is too warm, integrating the compressors
with outdoor air when free cooling is available, and locking out
the compressor when outdoor air temperature is too cold. The
detailed sequence of operation is described in the controls section
with a brief description of selected application items here.
Thermostat interface — The EconoMi$er IV control was
designed to work with conventional thermostats that have Y1
(cooling stage 1), Y2 (cooling stage 2), W1 (heat
(heat stage 2), and G (fan). In addition, the EconoMi$er IV will
support an occupied/unoccupied switch (typically integrated into
the thermostat or thermidistat). When the switch is closed, it
provides a 24 vac signal to the unit for occupied mode, and
provides no signal to indicate unoccupied mode. The
EconoMi$er IV control can be configured to allow different
minimum economizer damper positions and to allow the use of
mechanical cooling in the occupied mode.
Control features — The EconoMi$er IV controller provides
superior functionality for rooftop unit operation. EconoMi$er IV
control features are included as follows:
Remote minimum position control — The EconoMi$er IV
controller can be used with a field-supplied and field-installed
remote minimum position control switch that will enable and
disable the EconoMi$er IV to open or close the damper beyond
the minimum position for modified ventilation, providing 2 to 10
bdc output.
NOTE: Minimum position signal takes priority over the DCV
(Demand and Control Ventilation) maximum position signal.
Demand control ventilation (DCV) — The EconoMi$er IV has
DCV capability when using an IAQ sensor. This sensor is
typically installed in the return duct or occupied space.
implementing a DCV control scheme with the EconoMi$er IV,
the control algorithm will modulate the position of the damper
between two user-configured damper positions, Maximum DCV
Position and Minimum Occupied position. Design airflow rates
for these two damper positions should be such that when the
damper is at the Maximum DCV position, enough fresh
ventilation air will be brought in to remove contaminants and
CO generated by sources other than people (i.e., since in
2
unoccupied mode). The Maximum DCV position is intended to
Standard, Mild
Coastal
X
X
stage 1), W2
When
ENVIRONMENT*
Moderate Severe
Coastal Coastal
X
X
satisfy the IAQ "Base Ventilation Rate." The Minimum Occupied
position design airflow rate should be sufficient to satisfy
ventilation requirements for removing CO
including people at the maximum occupancy.
IAQ sensors — EconoMi$er IV can be utilized with any IAQ
(CO ) sensor that provides a 2 to 10 vdc output. The controller
2
will modulate the outdoor air damper to provide ventilation based
on the sensor output and the IAQ setting of the controller. When
used, an IAQ sensor will modulate the damper from the minimum
position (base ventilation rate based on CO
position (full occupancy ventilation rate).
Damper operation — The EconoMi$er IV allows the damper to
be configured for two adjustable damper positions including
maximum position and occupied minimum positions. The two
(2) position damper capability is a unique feature of EconoMi$er
IV and includes operation flexibility as follows:
1. Minimum Occupied Position: This adjustable position
allows a minimum ventilation airflow rate through the unit
during occupied periods (base ventilation rate).
2. Demand Control Ventilation (DCV) Maximum Position:
A DCV maximum occupied position is provided when
using an IAQ sensor for DCV. See DCV and Control
sections for sequence. The DCV Maximum Position limits
outdoor airflow into the rooftop when the DCV routine
overrides the mixed air sensor. Setting the DCV Maximum
Position of the outdoor-air damper prevents large amounts
of hot or cold air into the space.
IMPORTANT:When the DCV Maximum Position is set below
the minimum position, the minimum position overrides the
maximum position, negating most DCV functions.
Compressor staging — The EconoMi$er IV is an integrated
economizer and has the ability to utilize simultaneous outdoor air
and compressors. The EconoMi$er IV can be configured to
support economizer and compressor operation for up to 4
compressors. Only one or two compressor operation is available
1
with 3 to 12 / ton units.
2
Changeover strategies — The EconoMi$er IV controller can be
configured to accommodate all available economizer control
strategies that place the rooftop unit in
including:
Switch — Used when a remote signal from an energy
management system will enable and disable the EconoMi$er IV
(remote enable control).
Outdoor dry bulb — EconoMi$er IV will be enabled based on
the outside air temperature. This is provided standard with the
EconoMi$er IV.
Differential dry bulb — EconoMi$er IV will be enabled
whenever the outside air temperature is lower than the return-air
temperature.
189
Combined Coastal and
Industrial
Industrial
X X
from all sources
2
levels) to maximum
2
economizer mode