RONK ADD-A-PHASE Power Converter User Manual
- June 9, 2024
- RONK
Table of Contents
ADD-A-PHASE Power Converter
User Manual
ADD-A-PHASE Power Converter
Power Leads
Control Leads
EGC = Equipment
Grounding
Conductor
VERSING CONTACTOR MUST SWITCH PHASES C & B (L1 & L3).
CONNECTION CHECKLIS
Single-Phase to L1 & L2
At 30 Motor Starter
B to L3| EGC(s)
A to L2| T3 to T3
C to L1| T1 to T1
WIRING
- Size A, B, and C leads according to Article
- Size L1 and L2 for 125% MIN of the 10 FLA ADD-A-PHASE nameplate.
- Size EGC (see above) according to Article
- Size control leads – #16 MIN.
- See Article 455 of NEC for rules governing converter installations.
*” Do not connect control circuits or other single-phase loads to A phase (phase with highest voltage to ground) from the converter.
** VERIFY FIELD CONNECTION OF T1 AND T3 CONTROL LEADS: Energize the circuit up
to the motor starter. Do NOT turn on the starter. On the input side of the
motor starter, measure the phase-to-phase and phase-to-ground voltages to
verify the voltage on each pole. The T1 and T3 leads should be connected on
the motor side of the starter on the two poles that measure the lowest voltage
phase-to-ground. THESE MUST BE THE PHASES THAT REVERSE!
Motor off voltages on L1-L2 (C-A) and L3-L2 (B-A) depend on transformer tap
setting. Regardless of tap setting, VAB + VBC = VAC. For this reason, voltage
monitors and phase rotation monitors will not function correctly.
GENERAL INTERCONNECTION DIAGRAM FOR ADD-A-PHASE® | TYPE HD |
---|---|
REVISIONS | RONK ELECTRICAL INDUSTRIES, INC. NOKOMIS, ILLINOIS |
DATE | BY |
A | |
DRAWN – NCL | DRWG. NO. |
2-5409-1
B| | | 0| |
C| | | H| | | DATE – 11 /10/10
D| | | I| |
APP ‘D – PG
E| | | J| |
ADD-A-PHASE® GENERAL SETUP FOR TYPE HD
GETTING STARTED
Before installing the ADD-A-PHASE power converter, verify that the single-
phase supply voltage matches the converter rating. Consult the converter
nameplate for input voltage and amperage requirements.
The single-phase supply should be connected to the unit through a
disconnecting means (a circuit breaker or fused disconnect switch), utilizing
a time-delay type breaker or fuses. The ampere rating of the disconnecting
means shall not be less than 115% of the single-phase ampere rating of the
ADD-A-PHASE. A three pole across-the-line starter with appropriately sized
overloads is highly recommended for proper motor operation and protection. All
wiring should be done by a qualified electrician in accordance with all
applicable electrical codes. See Article 455 of the NEC® (and other applicable
Articles) for rules governing phase converter installations.
The following connections need to be made (see diagram on reverse side for
more details).
- Equipment ground(s):
- All equipment must be properly grounded. See Article 250 of the NEC for proper grounding and bonding.
- Input: (L1, L2) o Connect incoming single-phase service to L1 and L2.
- Motor Starter: (C, A, B) and (T1, T3)
- Connect the power leads C to L1, A to L2, and B to L3 on the line side of the starter.
- Connect the control leads T1 to T1 and T3 to T3 on the load side of the starter (with the motor leads).
Do not connect starter coils, control transformers, or single-phase loads to “A” phase (manufactured phase) from the converter. “A” phase may only be used to power the three-phase motor.
STARTING THE MOTOR
Close the single-phase disconnecting means, applying voltage to the
ADD-A-PHASE. Measure and record the voltages on the line side of the motor
starter. The measured voltages should match the Voltage Chart on the reverse
side of this page. Label the phase conductors “C”, “B”, and “A” as defined by
these voltage measurements. Proper identification of the phases is necessary.
You should now be ready to start the motor. Refer to the manual for component
descriptions.
When starting the motor, observe the following sequence of events.
- The motor is energized.
- The ADD-A-PHASE auxiliary relay should energize immediately and remain closed.
- The ADD-A-PHASE start contactor should engage.
- The motor should accelerate to full speed within 1 to 3 seconds.
- The start contactor will drop out and motor will continue running.
IF THE MOTOR DOES NOT REACH FULL SPEED WITHIN 15 SECONDS, SHUT OFF POWER TO
STARTER.
Place a voltmeter across T1 and T3 of the starter and reenergize the
starter long enough to read this voltage. The indicated phase-tophase voltage
on T1-T3 cannot drop more than 10% for the motor to start properly. If the
voltage is adequate and the motor does not start, refer to the Troubleshooting
Chart in the manual. DO NOT ALLOW THE START CONTACTOR TO REMAIN CLOSED FOR
MORE THAN 20 SECONDS LONGER PERIODS MAY DAMAGE THE EQUIPMENT!
BALANCING CURRENTS
In order to use these balancing procedures, the “C”, “B”, and “A” phases must
be properly identified. Phase identification can be verified by measuring the
motor off voltages on the line side of the motor starter. With “X” connected
on tap 2 or above, “A” will always have the highest phase-to-ground voltage,
and “A to C” will always have the highest phase-to-phase voltage. “X” is for
adjusting the tap setting on the ADD-A-PHASE autotransformer.
The three motor currents (“C”, “B”, and “A”) should be checked with a clamp-on
ammeter and balanced if necessary. The motor must be under normal operating
load when taking the readings. To balance the currents, follow these
procedures.
- Identify the phases at the motor starter as stated above. Then measure the three running amperages on the motor leads.
- If closer balance is desired, shut off and lock out the single-phase disconnecting means for the converter. Discharge all capacitors before beginning to adjust the unit for better current balance.
- If “A” current is considerably higher than “C”, a light load condition is indicated. If “A” is near FLA and “B” and “C” currents are higher, an overload condition is indicated. If either of these conditions exists, verify load is correct before proceeding with balancing.
- If “A” is high with “C” low and you have verified the motor is lightly loaded, disconnect some capacitance to bring “A” down and “C” up. If “B” amperage remains higher than both “A” and “C”, it may be necessary to move “X” down to a lower tap of the autotransformer. Note: Moving to a lower (higher) tap will decrease (increase) “A” phase voltages thereby decreasing (increasing) “A” phase current. Capacitance may need to be connected (disconnected) to readjust “A” phase current.
- If “A” is lower than “B” and “C”, more capacitance needs to be connected.
- If “B” is lower than “C”, then “X” needs to be moved to a higher tap.
- For future reference, record the final phase-to-phase voltages, phase currents, and motor off voltages.
If you have any questions about these procedures or need assistance with
balancing, call RONK at 217-563-8333.
Drwg. No. 2-5409-2
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