Flow switches
Thermal dispersion flow switches are factory mounted in the chilled water nozzle and are factory
wired to the chiller OptiView control panel. This solid state flow sensor has no internal moving
parts. It consists of a small internal heating element that uses the cooling effect from flowing fluids
to detect that flow has been established.
Waterbox drain and vent valves
Install drain and vent valves in the connections provided in the evaporator liquid heads. Johnson
Controls do not supply the drain and vent valves. These connections can be piped to drain if
required. They assist in the correct fill and vent of the chiller waterside before starting pumps to
ensure no voids exist that could cause damage from a water slug.
Waterbox fill and vent
After the water piping is completed, but before any waterbox insulation is applied, tighten the nuts
on the liquid head flanges. Torque to maintain between 30 ft·lb and 60 ft·lb (41 N•m and 81 N•m).
Gasket relaxation and handling during transit can cause the nuts to loosen. If water pressure is
applied before tightening is completed, the gaskets might be damaged and have to be replaced.
Fill the chilled water circuit, operate the pumps manually, and carefully check the evaporator water
heads and piping for leaks. Repair leaks as necessary.
Before initial operation of the unit, thoroughly vent the chilled water circuit of all air at the high
points.
Wiring connections
Unit power wiring
The factory mounted VSD does not require wiring to the compressor motor. The motor power
wiring is factory connected to the VSD. Refer to the
YVAM Unit Wiring and Field Control Modifications
Manual (Form 160.88-PW2)
. All wiring to the control panel is completed by the factory. A control
power transformer is factory furnished with the VSD.
Power wiring to the chiller is made through the single point power connection enclosure. Refer to
Field connections diagram for Model YVAM Single Point Power Connection Manual (Form 160.88-PW1)
for
details.
CAUTION
Do not cut wires to the final length or make final connections to the chiller power input terminals
without supervision from a qualified Johnson Controls representative.
Unit control wiring
If field wiring connections for commonly encountered control modifications are required, refer to
the
YVAM Unit Wiring and Field Control Modifications Manual (Form 160.88-PW2)
for details. Johnson
Controls do not supply the field wiring connections.
Note:
No deviations in the unit wiring from that shown on drawings furnished will be made
without prior approval of the Johnson Controls representative.
YVAM Air-Cooled Centrifugal Liquid Chiller
38
