First Co EVBQ (Variable Speed) - Manual (Page 6)

These fan coils are provided with a Class 2 transformer for 24volt control circuits. Should any add-on equipment also have
a Class 2 transformer furnished, care must be taken to prevent interconnecting outputs of the two transformers by using a
thermostat with isolating contacts.
CAUTION: Any devices such as fan switches or thermostats that have been furnished by the factory for
field installation must be wired in strict accordance with the wiring diagram that is supplied with the unit.
Failure to do so could result in damage to components and will void all warranties.
PROCEDURE 5 – REFRIGERANT TUBING CONNECTION AND EVACUATION
The EVBQ Fan Coil units are supplied with a direct expansion refrigerant coil and a thermostatic expansion valve. Check
that the correct thermostatic expansion valve, R-410A, is installed on the coil to match the outdoor unit refrigerant type.
CAUTION: Installer must check the coil metering device to see that it is the correct size and type to be
matched with the outdoor unit. (R-410A) Failure to follow this CAUTION could result in product or property
damage and minor personal injury.
Field-supplied refrigerant grade tubing must be sized in accordance with the outdoor unit manufacturer’s recommendations.
The entire suction tube must be insulated. Do not use damaged, dirty, or contaminated tubing because it may plug
refrigerant flow control device. Always evacuate coil and field-supplied tubing to 500 microns before opening outdoor unit
service valves.
CAUTION: A brazing shield MUST be used when tubing sets are being brazed to the unit connections to
prevent damage to the unit surface. Failure to follow this CAUTION could result in product and property
damage.
Units have sweat suction and liquid tube connections. Make suction tube connection first.
1. Cut tubing to correct length.
2. Insert tube into sweat connection on unit until it bottoms.
3. Braze connection using silver bearing or non-silver bearing brazing materials. Do not used solder (materials which
melt below 800 degree F).
CAUTION: Wrap a wet cloth around rear of fitting to prevent damage to TXV and factory-made joints.
Failure to follow this CAUTION could result in product and property damage.
4. Leak check the line connections and repair any leaks.
5. Evacuate coil and tubing system to 500 microns using deep vacuum method for 30 minutes.
PROCEDURE 6 – HOT WATER COIL PIPING
Piping Precautions
Flush all field water piping prior to connection to hot water coil to remove debris.
Use wet cotton rags to cool valve bodies when soldering.
Open all valves (midway for hand valves, manually open on motorized valves) prior to soldering.
When soldering to bronze or brass, heat the piping while in the socket/cup and begin introducing the solder when the flux
boils rapidly. Avoid direct flame into the solder joint.
Heat can only be applied to the cup of the valve body for a minimal time before damage occurs (even with the use of wet
rags.
Avoid rapid quenching of solder joints as this will produce joints of inferior quality.
Connect all piping per accepted industry standards and observe all regulations governing installation of piping systems.
When all connections are complete the system must be pressure tested. Repair any solder joint leaks and gently tighten
any leaking valve packing nuts and piping accessories as required. Hydronic systems are not designed to hold pressurized
air and should only be tested with water.
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