Sterling AquaSnap 30RA010-055 - Manual (Page 24)

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Optional Factory-Installed Hydronic Package —
If the chiller has factory-installed chilled fluid pumps, specific
steps should be followed for proper operation.
The pump(s) in the hydronic package come factory
pre-wired into the main unit power supply/starter. In order to
check proper pump rotation, use the Service Test function to
test the condenser fans and observe them for proper rotation
(counter clockwise when viewed from the top). If fans turn
correctly, the pumps will rotate correctly. Clockwise rotation of
the pump motor cooling fans can also be used to determine that
pumps are rotating correctly.
Use Service Test function to test operation of pumps. Verify
that the flow switch input is made when the pump is running.
For dual pump hydronic systems, the control only uses one
pump at a time. Consult the Installation Instructions supplied
with this chiller and use the circuit setter balancing valve
installed in hydronic package to adjust fluid flow rate.
Cooler Pump Control — The 30RA AquaSnap® ma-
chines equipped with a factory installed pump package are
configured with the Cooler Pump Control (CPC) [Configura-
tion, OPT1] ON.
Machines not equipped with a pump package are config-
ured with the cooler pump control OFF. It is recommended that
the machine control the chilled water pump. If not, a 5-minute
time delay is required after the command to shut the machine
down is sent before the chilled water pump is turned off. This is
required to maintain water flow during the shutdown period of
the machine.
With or without this option enabled, the cooler pump relay
will be energized when the machine enters an ON status (i.e.,
On Local, On SCN, On Time). An A207 - Cooler Freeze
Protection Alarm, will energize the cooler pump relay also, as
an override. The cooler pump relay will remain energized if the
machine is in MODE 10 – Minimum Off Time.
Cooler Pump Sequence of Operation — At any-
time the unit is in an ON status, as defined by the one of the
following conditions, the cooler pump relay will be enabled.
1. The Enable-Off-Remote Switch in ENABLE,
(CTRL=0).
2. Enable-Off-Remote Switch in REMOTE with a
Start-Stop remote contact closure, (CTRL=0).
3. An Occupied Time Period from an Occupancy Schedule
in combination with items 1 or 2, (CTRL=2).
4. A SCN Start-Stop Command to Start in combination
with items 1 or 2, (CTRL=3).
As stated before, there are certain alarm conditions and
Operating Modes that will turn the cooler pump relay ON. This
sequence will describe the normal operation of the pump
control algorithm.
When the unit cycles from an “On” state to an “Off” state,
the cooler pump output will remain energized for the Cooler
Pump Shutdown Delay (PM.DY) [Configuration, OPT1]. This
is configurable from 0 to 10 minutes. The factory default is 1
minute. If the pump output was deenergized during the transi-
tion period, the pump output will not be energized.
NO INTEGRAL PUMP — SINGLE EXTERNAL PUMP
CONTROL — With a single external pump, the following
options must be configured:
• Cooler Pump Control (CPC) [Configuration, OPT1]
OFF.
• Cooler Pump 1 Enable (PM1E) [Configuration, UNIT]
NO.
• Cooler Pump 2 Enable (PM2E) [Configuration, UNIT]
NO.
The maximum load allowed for the Chilled Water Pump
Starter is 5 VA sealed, 10 VA inrush at 24 volts. The starter coil
is powered from the chiller control system. The starter should
be wired between TB5-11 and TB5-13. If equipped, the field-
installed chilled water pump starter auxiliary contacts should
be connected in series with the chilled water flow switch.
The Cooler Pump Relay will be energized when the
machine is “On.” The chilled water pump interlock circuit
consists of a chilled water flow switch and a field-installed
chilled water pump interlock. If the chilled water pump inter-
lock circuit does not close within five (5) minutes of starting,
an A200 — Cooler Flow/Interlock failed to close at Start-Up
alarm will be generated and chiller will not be allowed to start.
If the chilled water pump interlock or chilled water flow
switch opens for at least three (3) seconds after initially being
closed, an A201 — Cooler Flow/Interlock Contacts Opened
During Normal Operation Alarm will be generated and the ma-
chine will stop.
NO INTEGRAL PUMP — DUAL EXTERNAL PUMP
CONTROL
— With two external pumps, the following
options must be configured:
• Cooler Pump Control (CPC) [Configuration, OPT1] ON.
• Cooler Pump 1 Enable (PM1E) [Configuration, UNIT]
YES.
• Cooler Pump 2 Enable (PM2E) [Configuration, UNIT]
YES.
The maximum load allowed for the Chilled Water Pump
Starters is 5 VA sealed, 10 VA inrush at 24 volts. The starter
coil is powered from the chiller control system. The starter for
Chilled Water Pump 1 should be wired between TB5-11 and
TB5-13. The starter for Chilled Water Pump 2 should be wired
between TB5-15 and TB5-13. A field-installed chilled water
pump interlock for each pump must be connected to each
pump’s interlock points on the Main Base Board. The Chilled
Water Pump 1 Interlock, CWP1, must be connected to MBB-
J7-1 and –2. The Chilled Water Pump 2 Interlock, CWP2, must
be connected to MBB-J7-3 and –4. The chilled water pump
interlock contacts should be rated for dry circuit application
capable of handling 5 vdc at 2 mA.
SINGLE INTEGRAL PUMP CONTROL — With a single
pump, the following options must be configured:
• Cooler Pump Control (CPC) [Configuration, OPT1] ON.
• Cooler Pump 1 Enable (PM1E) [Configuration, UNIT]
YES.
• Cooler Pump 2 Enable (PM2E) [Configuration, UNIT]
NO.
With a single integral pump, the Cooler Pump Starter will
be energized when the machine is occupied. As part of the
factory-installed package, an auxiliary set of contacts is wired
to the MBB to serve as Chilled Water Pump Interlock. When
the mechanical cooling is called for, the pump interlock and
flow switch is checked. If the circuits are closed, the machine
starts its capacity routine. If the auxiliary contact interlock does
not close within 25 seconds of the ON command, a T190 —
Cooler Pump 1 Aux Contacts Failed to Close at Start-Up Alert
will be generated and the pump shut down. The unit will not
be allowed to start. If the chilled water flow switch does not
close within one (1) minute, two alarms will be generated. A
T192 — Cooler Pump 1 Failed to Provide Flow at Start-Up
Alert and an A200 – Cooler Flow/Interlock failed to close at
Start-Up will be generated and chiller will not be allowed to
start.
If the chilled water flow switch opens for at least 3 seconds
after initially being closed, a T196 — Flow Lost While Pump 1
Running Alert and an A201 — Cooler Flow/Interlock Contacts
Operation of pump in wrong direction, even for a few
seconds, can cause irreversible damage to pump impeller
and housing. Always verify correct wiring/pump rotation
before operation.