Catalogue

CAB-PRC001-EN 63
Mechanical Specifications
Ball Valve Supply, Manual Circuit Setter Return
A ball valve is provided on the supply with a manual circuit setter on the return. The manual circuit
setter is a combination flow-setting device and shutoff valve that includes two Schrader ports. The
maximum working pressure of the valve is 300 psig.
Ball Valve S & R, Auto Circuit Setter Return
Ball type end valves are mounted on the supply and return, with an additional auto circuit setter
mounted on the return. The auto circuit setter is an automatic flow control valve that is sized to
allow a specific flow rate through the coil. Auto circuit setters also include two P/T plugs and have
a maximum working pressure of 400 psig.
Control Valve Options
All control valves have a maximum working pressure of 300 psig. The maximum entering water
temperature of the valve is 200°F.
Two-Way, Two-Position Control Valves
When using two-way valves, use some means such as a pump and chiller bypass to ensure the
maximum closed off DP rating of the valve is not exceeded. Two-way, two-position valves are rated
for a maximum pressure differential across the valves of 30 psig. The valves are also available with
a close-off pressure of 50 psig. The valve actuator is easily removable for service without removing
the valve body from piping.
Three-Way, Two-Position Control Valves
Normally open three-way, two-position valves are rated for a maximum 28 psig pressure
differential across the valve. Normally closed three-way two-position valves are rated for a
maximum 20 psig pressure differential across the valve. All 3-way valve piping packages include
a bypass line with a balance fitting to set flow through the bypass line. The balance fitting has a
maximum working pressure of 150 psig. The valves are also available with a maximum close-off
pressure of 50 psig. The valve actuator is easily removable for service without removing the valve
body from piping.
Modulating Control Valves
Two-way and three-way modulating valves are rated for a maximum 50 psig pressure differential
across the valve. Modulating valves are available in Cv values of 0.7, 1.5, 2.5, and 4.0.
Electric Heat Coil
A single- or dual-stage electric heating coil is provided as the total source of heat. Electric heat coils
are open-wire type. The coils are a nickel-chromium element design. The electric heat operates at
the same voltage as the unit, and only a single power connection is necessary.
All units with factory-mounted electric heat are UL-listed and interlocked with the fan motor switch.
A call for electric heat operation will turn the fan on. Motors controls are synchronized with
fan/valve operation to ensure safe operation and to ensure that two modes of heat are not
operating simultaneously. A transformer is supplied on any voltage unit, eliminating the need for
field installation of a step-down transformer. Unit-mounted quiet magnetic relays are supplied on
all voltages. A line-break high temperature cutout with automatic reset is provided as an integral
part of the elements to de-energize the electric heat in the event of a malfunction.
Filters
Filters are concealed from sight and easily removable. Filters are located behind an integral access
door on horizontal type units. Filters are either 1” throwaway, MERV 8, or MERV 13.
Units equipped with 1” MERV 8 filters have a rating based on ASHRAE Standard 52.2. The average
dust spot efficiency is no less than 35 to 40 percent when tested in accordance with ASHRAE 52.1
atmospheric dust spot method.
CAB-PRC001-EN.book Page 63 Tuesday, May 8, 2012 10:11 AM