Step 5 -- Make Electrical Connections; Power Supply; Power Wiring; Control Power - Carrier AQUASNAP 30RB060-390 Installation Instructions Manual

Step 5 -- Make Electrical Connections
Electrical shock can cause personal injury and death. Shut
off all power to this equipment during installation. There
may be more than one disconnect switch. Tag all discon-
nect locations to alert others not to restore power until work
is completed.
POWER SUPPLY The electrical characteristics of the
available power supply must agree with the unit nameplate
rating. Supply voltage must be within the limits shown.
Some units have options for multiple power connections.
See Tables 8-13 for electrical requirements and Fig. 48 for
electrical connection information.
IMPORTANT: Operating unit on improper supply ]
voltage or with excessive phase imbalance constitutes
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abuse and may adversely affect Carrier warranty.
POWER WIRING All power wiring must comply with
applicable local and national codes. Install field-supplied
branch circuit fused disconnect per NEC of a type that can be
locked OFF or OPEN. Disconnect must be within sight and
readily accessible from the unit in compliance with NEC
Article 440-14. In the power box, 7/8in. holes are provided for
power entry. The holes will need to be enlarged to accept the
appropriate conduit. NEC also requires all conduits fiom a
conditioned space to the power box(es) be sealed to prevent
airflow and moisture into the control box.
Duplex units require at least two separate power supplies, at
least one for each module, depeMing on the power supply
option ordered. See Fig. 48.
General Wiiqng Notes:
1. The control circuit does NOT require a separate power
source. A step-do,a_ transformer fiom the main three-
phase power supply obtains control circuit power. Be sure
that the appropriate connection tap is connected on all
transforlners for the supply voltage. Up to two terlninal
blocks are provided for field-wired control devices.
2. Cooler and pump heaters (if factory installed) are wired
in the control circuit so they are operable as tong as the
main power supply to the unit is ON. A factory-installed
and set overload device protects them.
NOTE: The field-supplied disconnect should never be off
except when unit is being sm_iced or is to be down for a pro-
longed period, in which case the cooler should be drained.
3. Power entry depends on the size and power entry option
ordered.
4. Maximum field wire sizes allowed by lugs on terlninat
block/non-fused disconnect are listed in Tables 8 and 9.
5. Terminals for field power supply are suitable for copper
conductors. Insulation must be rated 75 C minilnum.
!
IMPORTANT: TO ensure power to the heaters, make ]
sure power to the unit is always on (except during ser-
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vice or a prolonged shutdown).
Proper rotation of condenser tan(s) and pump(s) IVlUSTbe
verified before pumps or compressors are started. Consult
the Controls, Start-Up and Operation guide provided with
30RB060-390 units for correct procedure, hnproper pump
rotation can cause perlnanent dmnage to pump impeller
and housing. If pmnp(s) have been relnoved for trilnlning,
verify wiring is reconnected in the original manner.
CONTROL POWER Control power is obtained fiom the
main power supply and does NOT require a separate source. A
toggle switch (marked SW2 on the unit label diagram and by
the switch) albws the control circuit to be manually
disconnected when necessary. Cooler and pump heaters (if
installed) are in an inoperable state when this switch is in the
Offposition.
IMPORTANT: For 208-v systems, the connection tap
t\_r all transforlners must be changed. The factory
default setting is for 230-v. Failure to connect to the
proper tap may result in unreliable operation.
FIELD CONTROL OPTION WIRING Install field control
wiring options. See Fig. 48. Some options, such as 4 to 20 mA
Delnand Limit that requires the Energy Management Module,
may require that accessories be installed first if not factory
installed for terminal connections.
DUAL CHILLER LEAVING WATER SENSOR If the Dual
Chiller algorithln is used and the machines are installed in
parallel, an additional chilled water sensor must be installed for
each chiller. For 30RB315-390 units, a factory-supplied ther-
mistor and well are shipped in the control box of each. Install
the well in the comlnon leaving water header. See Fig 23. DO
NOT relocate the chiller's leaving water thermistors. They
must remain in place for the unit to operate properly.
The therlnistor well is a 1/4in. NPT fitting for securing the
well in the piping. The piping must be drilled and tapped t;_r
the well. Select a location that will allow for relnovat of the
thermistor without any restrictions. See Fig. 49.
Once the well is inserted, install the therlnistors. Insert the
thermistor into the well until the o-ring reaches the well body.
Use the nut on the therlnistor to secure the thermistor in place.
Once the therlnistor is in place, it is recomlnended that a
thermistor wire loop be made and secured with a wire tie to the
chilled ,a_aterpipe. This will aid in thermistor retention in the
well. See Fig. 50.
For 30RB315-390 units, as well as all units using the dual
chiller atgorithin, a Carrier Comt_rt Net_x_rk, _ R)(CCN) bus
must be connected between the two modules. See the
Carrier Comfort Network Colrnnunication Bus Wiring for ad-
ditional inti_nnation.
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