Specifications

14
in this document. The values on the tag
must be used in lieu of any other values.
During the run test at the factory, the
pressure drop listed on this tag was
observed to be the exact pressure drop of
the unit when all other conditions were at the
design conditions. Each chiller in a group
may have individual and unique values as no
two tubing bundles are exactly alike.
Figure 9 – Example of the Pressure Loss
in Unit Tag
When setting proper flow rates through a
fluid loop, it will be necessary to measure the
pressure at both the inlet and the outlet of
the same circuit, and then subtract the higher
value from the lower value. The result is the
pressure drop through that circuit. The
target pressure drop is the value listed on the
Pressure Loss in Unit tag (see Figure 9). In
order to ensure proper flow through the fluid
circuits, make certain the pressure drop
through the loop is equal to or slightly greater
than the value listed on the Pressure Loss in
Unit tag.
Each inlet and outlet tube has a pressure
test needle valve installed into it. This
needle valve has a special metric flare
connection so it requires a specialized tool,
available from Yazaki, in order to access the
fluid circuit for pressure readings.
As an alternative, there is an accessory
kit available to replace the metric flare
needle valves with ¼” SAE flare valves. It
may also be possible to procure ¼” SAE
flare needle valves locally for the purpose.
FLOW SWITCH
The factory-installed flow switch is
shipped disconnected from the water piping
in order to help prevent damage during
shipment. After the factory run test is
completed, the flare nuts that connect the
water pipes to the differential pressure flow
switch are disconnected and plugged with a
small plastic cap.
One of steps of the installation process is
to locate the flow switch, remove the plastic
plugs, and attach the flare nuts to the flow
switch once again. If this step is forgotten,
then water will leak from these pipes as the
fluid circuit is being filled.
The flow switch must be set in order to
perform properly. In order to set the switch,
reduce the pressure drop through the
chilled/hot water circuit to ½ of the value
listed on the Pressure Loss in Unit tag,
adjust the flow switch until it opens at this
pressure setting, then restore the chilled/hot
water circuit to the normal pressure drop.
This method will test simultaneously set up
the flow switch as well as test its function.
CHILLED/HOT WATER PIPING
Figure 10 – Chilled Water Piping
CAUTION
1. DO NOT EXCEED 80 – 120% OF
STANDARD CHILLED WATER FLOW.
2. DO NOT EXCEED 85.3 PSI (588 kPa) IN THE
CHILLED WATER CIRCUIT AT THE
ABSORPTION CHILLER.
3. DO NOT INSTALL ANY VALVES IN THE
EXPANSION LINE.
A balance valve should be installed at the
chilled water outlet and a stop valve should
be installed at the chilled water inlet.
After thoroughly testing for leaks, insulate
the piping circuit, ensuring an adequate
vapor barrier is obtained. Be sure to allow
access to any valves, wells, and ports that
may be present.