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3.0 ELECTRICAL CONNECTIONS
Before proceeding with the electrical connections, make certain that the volts, hertz, and phase
correspond to that specified on the unit electrical nameplate. Use copper conductors only.
3.1
Electrical Service
Check to be sure the service provided by the utility is sufficient to handle the additional load imposed
by this equipment.
3.2
Nameplate Ratings
Refer to the unit electrical nameplate for equipment electrical requirements. Minimum circuit ampacity,
(MCA) also known as wire sizing amps, will dictate the minimum required wire gauge. Maximum
overcurrent protection (MOP) device amps will dictate the maximum circuit breaker or fuse size.
3.3
Grounding
The unit cabinet must have an uninterrupted true earth ground. An electrical ground wire of adequate
size must be connected to the ground lug provided inside the main electrical box.
3.4
Voltage Tolerance
The supply voltage to the unit must be within 10% of the voltage indicated on the unit electrical
nameplate. Phase to phase imbalance must not exceed 3%. The local utility company should be
contacted for correction of improper line voltage. Deviation from voltage ratings can cause premature
failures and possibly void unit warranties.
Check the wiring connections in the unit control panel to ensure they are tight. Screw
terminals may become loose in transit. Tightening of wiring connections is the responsibility
of the installing contractor.
3.5
Remote Shutdown
Every Data Aire chilled water unit has remote shutdown contacts. These are intended for a field
supplied dry contact or switch to be wired across two terminals. When the contact or switch opens, the
control circuit power is interrupted and the unit shuts down, including the control panel. The control
circuit is 24 VAC and the field provided contact or switch should have a minimum rating of 10 amps.
The remote shutdown contacts are always terminals #1 and #2 on the terminal block designated
TB1. The unit will ship with a factory wired metal jumper clip that connects terminal #1 to terminal #2.
Remove this clip prior to installing the field wires.
3.6
Remote Alarm Contacts
The
DAP III
, microprocessor control panel provides a remote alarm output contact that can be field
accessed on terminals #11 and #13 of terminal block TB1. This is a Normally Open, Close on Alarm,
dry contact, intended to be used in a control circuit not exceeding 5 amps at 24 VAC.
This programmable output contact will close on a failure and remain closed until the alarm is no
longer present. Three additional alarm output contacts come with the optional relay module. The terminal
designations for these alarm output contact pairs are #40 and #42; #43 and #45; and #48 and #50.
