Motor leakage current detector, devices using same and related methods
A motor leakage current detector and/or a heat compensating circuit, devices using same and related methods are disclosed herein. Included are a uniquely wired current transformer to allow for polarity agnostic leakage current detection, a leakage current detector using same and having a notifier to alert a user. In other forms, an accessory power cord and power strip are disclosed capable of detecting early motor failure conditions. In still other forms, other machinery failure early warning systems are disclosed as are numerous motor operated devices using same including without limitation pumps.
1. A pump comprising:
a fluid inlet;
a fluid outlet;
an electric motor operable to pump fluid from the fluid inlet toward the fluid outlet;
one or more power conductors to provide electrical power to the electric motor from a power source; and
a leakage current detector having a current transformer operably connected to the one or more power conductors and a leakage current detection circuit connected to the current transformer, the leakage current detection circuit configured to:
detect leakage current flowing in the one or more power conductors using the current transformer without operating the electric motor; and
output a signal to provide notice of a problem with the pump based at least in part on the detected leakage current.
2. The pump of claim 1 wherein the current transformer includes at least one primary winding connected to a Line conductor and/or a Neutral conductor of the one or more power conductors and a secondary winding coupled to the at least one primary winding to detect leakage current through the Line conductor and/or Neutral conductor.
3. The pump of claim 2 wherein the secondary winding of the current transformer is electrically connected to the leakage current detection circuit.
4. The pump of claim 2 wherein the at least one primary winding includes a first primary winding connected to the Line conductor and a second primary winding connected to the Neutral conductor.
5. The pump of claim 1 wherein the leakage current detection circuit is configured to output the signal when detected leakage current exceeds a predetermined threshold.
6. The pump of claim 5 wherein the predetermined threshold is 0.05 mA.
7. The pump of claim 1 wherein to output the signal includes outputting an alert signal when leakage current indicates an advance motor failure condition exists and outputting an alarm signal when an imminent motor failure condition exists.
8. The pump of claim 7 wherein the alert signal is output when the detected leakage current is between about 0.05 mA and 6 mA and wherein the alarm signal is output when the detected leakage current is above 6 mA.
9. The pump of claim 1 wherein the leakage current detector further includes:
a first switch operable to permit current to flow through a Line conductor of the one or more power conductors relative to the electric motor; and
a second switch operable to permit current to flow through a Neutral conductor of the one or more power conductors relative to the electric motor,
wherein to operate the electric motor both the first switch and the second switch are closed and to detect leakage current without operating the electric motor includes the leakage current detection circuit causing one of the first switch and the second switch to be open and the other of the first switch and the second switch to be closed.
10. The pump of claim 9 wherein the first switch comprises a relay switch in parallel with a triac, wherein the at least one of the relay switch and the triac are operable to permit current to flow through the Line conductor relative to the electric motor.
11. The pump of claim 1 further comprising a fluid level sensor to detect a fluid level, wherein the electric motor is operated when the detected fluid level exceeds a predetermined threshold.
12. The pump of claim 1 wherein to output the signal includes wirelessly transmitting a message to a user advising when the detected leakage current exceeds a predetermined threshold.
13. The pump of claim 1 wherein the leakage current detection circuit is further configured to inhibit operation of the motor when the detected leakage current exceeds a predetermined threshold.
14. The pump of claim 13 wherein the predetermined threshold is 6 mA.
15. A pump system comprising:
a DC pump including a battery and communication circuitry;
an AC pump including:
an electric motor;
a leakage current detector configured to detect leakage current in the electric motor; and
communication circuitry configured to wirelessly communicate with the DC pump.
16. The pump system of claim 15 wherein at least one of the DC pump and the AC pump are configured to wirelessly transmit information relating to the pump system to a remote device of a user.
17. The pump system of claim 16 wherein the at least one of the DC pump and the AC pump are configured to communicate via at least one of wireless fidelity (Wi-Fi), Cellular, radio frequency (RF), infrared (IR), Bluetooth (BT), Bluetooth Low Energy (BLE), Zigbee and near field communication (NFC).
18. The pump system of claim 15 wherein the DC pump includes a battery charger configured to be connected to an AC power source and operable to charge the battery.
19. The pump system of claim 15 wherein the DC pump operates using electric power of the battery when AC power is unavailable to the AC pump.