Daikin EWWQ440AJYNN/A [117/130] Standard controls

Daikin EWWQ950AJYNN [117/130] Standard controls
ESIE07-05 Maintenance
Part 5 – Maintenance 5–5
3
5
1
5
1.3 Standard Controls
High pressure
control
The high pressure switch will shut-down the compressor when the discharge pressure exceeds the
setting point value.
Warning: during testing, stand by the emergency stop switch on control panel, to shut the unit down
should the safety control malfunction. Be sure that the installed gauge is accurately adjusted.
Phase/voltage
monitor
The phase/voltage monitor is a device which provides protection against three-phase electrical motor
loss due to power failure conditions, phase loss, and phase reversal. Whenever any of these
conditions occur, a contact opens to the microprocessor which then de-energizes all inputs. When
proper power is restored, contacts close and microprocessor enables compressors for operation.
When three-phase power has been applied, the output relay should close and the "run light" should
come on. If the output relay does not close, perform the following tests:
1 Check the voltages between L1-L2, L1-L3 and L2-L3 (L1, L2, L3 are the three phases). These
voltages should be approximately equal and within + 10% of the rated three-phase line-to-line
voltage.
2 If these voltages are extremely low or widely unbalanced check the power system to determine the
cause of the problem.
3 If the voltages are good, using a phase tester, verify that phases are in A, B, C sequence for L1,
L2 and L3.
Correct rotation is required for compressor operation. If required to do so by phase sequence, turn off
the power and interchange any two of the supply power leads at the disconnect. This may be
necessary as the phase voltage monitor is sensitive to phase reversal. Turn on the power. The output
relay should now close after the appropriate delay.
ESIE07-05.book Page 5 Friday, December 21, 2007 3:21 PM

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