Franklin motor - QD 3 wire control box

Single-phase three-wire submersible motors require the use of control boxes. Operation of motors without control boxes or with incorrect boxes can result in motor failure and voids warranty.

Control boxes contain starting capacitors, a starting relay, and, in some sizes, overload protectors, running capacitors and contactors.

Ratings through 1 hp may use either a Franklin Electric

solid state QD or a potential (voltage) type starting relay,

while larger ratings use potential relays.

QD solid state Relay

There are two elements in the relay: a reed switch and a triac. The reed switch consists of two tiny rectangular blade-type contacts, which bend under magnetic flux. It is hermetically sealed in glass and is located within a coil, which conducts line current. When power is supplied to the control box, the main winding current passing through the coil immediately closes the reed switch contacts. This turns on the triac, which supplies voltage to the start winding, thus starting the motor.

Once the motor is started, the operation of the QD relay is an interaction between the triac, the reed switch and

the motor windings. The solid state switch senses motor speed through the changing phase relationship between start winding current and line current. As the motor approaches running speed, the phase angle between the start current and the line current becomes nearly in phase. At this point, the reed switch contacts open, turning off the triac. This removes voltage from the start winding and the motor continues to run on the main winding only. With the reed switch contacts open and the triac turned off, the QD relay is ready for the next starting cycle.

CAUTION: The control box and motor are two pieces of one assembly. Be certain that the control box and motor hp and voltage match. Since a motor is designed to operate with a control box from the same manufacturer, we can promise warranty coverage only when a Franklin control box is used with a

Franklin motor.

Ohmmeter Test

QD, Solid State Control Box (Power Off)

A. START CAPACITOR AND RUN CAPACITOR IF

APPLICABLE (CRC)

1. Meter Setting: R x 1,000.

2. Connections: Capacitor terminals.

3. Correct meter reading: Pointer should swing toward zero, then back to infinity.

B. Q.D. (BLUE) RELAY

Step 1. Triac Test

1. Meter setting: R x 1,000.

2. Connections: Cap and B terminal.

3. Correct meter reading: Infinity for all models.

Step 2. Coil Test

1. Meter Setting: R x 1.

2. Connections: L1 and B.

3. Correct meter reading: Zero ohms for all models.

CAUTION: The tests in this manual for components such as capacitors, relays, and QD switches should be regarded as

indicative and not as conclusive. For example, a capacitor may test good (not open, not shorted) but may have lost some

of its capacitance and may no longer be able to perform its function.

Checking and Repairing Procedures (Power On)

A: VOLTAGE MEASUREMENTS

Step 1. Motor Off

1. Measure voltage at L1 and L2 of pressure switch

or line contactor.

2. Voltage Reading: Should be ± 10% of

motor rating.

Step 2. Motor Running

1. Measure voltage at load side of pressure switch

or line contactor with pump running.

2. Voltage Reading: Should remain the same except

for slight dip on starting. Excessive voltage

drop can be caused by loose connections, bad

contacts, ground faults, or inadequate

power supply.

3. Relay chatter is caused by low voltage or

ground faults.

B. CURRENT (AMP) MEASUREMENTS

1. Measure current on all motor leads.

2. Amp Reading: Current in red lead should momentarily be high, then drop within one second to values in table 13. This verifies relay or solid state relay operation. Current in black and yellow leads should not exceed values in table 13 below.

3. Relay or switch failures will cause red lead current to remain high and overload tripping.

4. Open run capacitor(s) will cause amps to be higher than normal in the black and yellow motor leads and lower than normal in the red motor lead.

5. A bound pump will cause locked rotor amps and overloading tripping.

6. Low amps may be caused by pump running at shutoff, worn pump, or stripped splines.

7. Failed start capacitor or open switch/relay are indicated if the red lead current is not

momentarily high at starting.

1/3 - 1 hp QD RELAY 280 10_ 4915 Sixth digit depends on hp

Table 13 Single-Phase Motor Specifications (60 Hz) 3450 rpm

(1) Main winding - yellow to black

Start winding - yellow to red

(2) Y = Yellow lead - line amps

B = Black lead - main winding amps

R = Red lead - start or auxiliary winding amps

(3) Control Boxes date coded 02C and older have 35 MFD run capacitors. Current values should be Y14.0 @ FL and Y17.0 @ Max Load.

B12.2

B14.5 R4.7 R4.5

(4) Control Boxes date coded 01M and older have 60 MFD run capacitors and the current values on a 4" motor will be Y23.0 @ FL - Y27.5 @ Max Load.

B19.1 B23.2

R8.0 R7.8

(5) Control Boxes date coded 01M and older have 60 MFD run capacitors and the current values on a 6" motor will be Y23.0 @ FL -Y27.5 @ Max Load.

B18.2 B23.2

R8.0 R7.8

Performance is typical, not guaranteed, at specified voltages and specified capacitor values. Performance at voltage ratings not shown is similar, except amps vary inversely with voltage.