Emerson 2 - Manual (Page 8)

Introduction
2
1.3 Optional Features
4 or 5 Ton Unit With 3 Ton Openings
The 4 or 5 ton units with 3 ton supply and return openings are designed to replace 3 ton wall mounted
air conditioners using existing wall openings. The economizer/fresh air option is not available. Return
filter is located in the return air grille and must be selected from accessory equipment.
Scroll Compressor—Optional on 1.5, 2 and 3 Ton Units
The quiet and efficient scroll compressor features a suction gas cooled motor, internal centrifugal oil
pump, vibration isolating mountings and internal thermal overloads.
Compressor Location
The standard compressor location is on the right when viewing the unit when it is mounted on the
wall. The optional compressor location is on the left, to improve serviceability of the compressor when
the unit is installed as one unit of a pair.
Compressor Crankcase Heater
An optional compressor crankcase heater is available for use with the scroll compressor but is not
required because the refrigerant charge of the InteleCool2 unit with scroll compressor is less than the
compressor critical charge.
High Ambient Condenser
This option is provided for applications where the ambient temperature exceeds the normal design
capabilities of the units. It consists of a condenser motor and fan blades which are sized to provide
additional airflow across the condenser coil. Designed for applications up to 125°F (51°C) ambient.
Heat
Heat is provided in a single stage from an open wire electric resistance element. Heating capacity
options available are 5 kW, 10 kW, and 15 kW depending on unit model size.
Economizer
The Economizer allows outside air to be introduced to the space through the evaporator filter when
conditions are favorable for Economizer cooling. It contains a modulating damper, spring return
direct drive actuator, enthalpy control for switchover, outside air hood and a mixed air controller set
at 55°F (12.8°C). Mechanical cooling and Economizer operation do not operate simultaneously.
Fresh Air Damper
Allows outside air to be brought in to meet indoor air requirements. Air is drawn in through the evap-
orator filter. The amount of air to be introduced to the space is field selectable.
Panel Colors
Optional color choices for the steel panels are almond (light tan, the color option for the original
InteleCool), desert brown, or bright white.
Lockout Relay
The lockout relay latches the detection of a high-pressure condition in the refrigeration circuit and
prohibits operation of the compressor until the abnormal pressure conditions are acknowledged. The
lockout relay is reset by cycling the unit main power or by changing the setpoint on the thermostat to
temporarily eliminate a call for cooling. A normally open set of contacts is provided to terminals 2 and
3 of the customer terminal strip for monitoring the status of the lock out relay when this option is sup-
plied without the Common Alarm option.
Common Alarm
The common alarm provides the necessary components to detect high pressure, low pressure, high
temperature, or loss of indoor airflow, and to provide a customer signal via a contact closure. To detect
low pressure, the optional low pressure switch with bypass, T-pack1 or T-pack2 must also be selected.
Soft Start
Provides a PTC resistor to assist the start of the compressor motor in low voltage operation. Available
only on single phase units.