US3745781A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Time delay circuit for a motor compressor system
Assignee: Rheem Manufacturing Co
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Filing: 1971-07-02
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Granted: 1973-07-17
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Expires: 1991-07-02
Abstract
Abstract A time delay control circuit for an air conditioning system prevents restarting of the compressor motor until the pressure on the output side of the compressor drops below a fixed value. This arrangement prevents constant recycling of the compressor motor. The control circuit includes a thermostatically operated relay in series with a pair of parallel relays. One of the parallel relays is normally closed and opens whenever pressure on the high side of the compressor reaches a predetermined normal value. The other parallel relay is normally open and closes whenever power is supplied to the compressor motor. The motor power circuit includes a third normally open relay in series with the motor. The third relay is closed whenever the thermostatically operated relay and either of the parallel relays complete the control circuit.
Inventors
- 👤 R Rasmussen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:08
CPC Classifications
F; F25; F25B; F25B49/00; F25B49/02; F25B49/025; F25B2600/00; F25B2600/23
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
148 words
A time delay contol circuit for a motor-compressor system to prevent recycling thereof, said system including a compressor, a compressor motor and means for supplying electric power to said motor including a normally open power relay in series with said motor, said control circuit comprising, in combination: thermostatically responsive relay means, first normally open relay means in series with said thermostatically responsive relay means, said first relay means operative to close whenever power is supplied to said motor, and normally closed environmental responsive relay means also in series with said thermostatically responsive relay means and in parallel with said first relay means, said environmental responsive relay means operative to open whenever the sensed environmental condition of said compressor differs from a predetermined non-operating condition, said control circuit operative to close said power relay whenever said thermostatically responsive relay and at least one of said other relays are closed.
Claim 2
Dependent Claim
148 words
A time delay contol circuit for a motor-compressor system to prevent recycling thereof, said system including a compressor, a compressor motor and means for supplying electric power to said motor including a normally open power relay in series with said motor, said control circuit comprising, in combination: thermostatically responsive relay means, first normally open relay means in series with said thermostatically responsive relay means, said first relay means operative to close whenever power is supplied to said motor, and normally closed environmental responsive relay means also in series with said thermostatically responsive relay means and in parallel with said first relay means, said environmental responsive relay means operative to open whenever the sensed environmental condition of said compressor differs from a predetermined non-operating condition, said control circuit operative to close said power relay whenever said thermostatically responsive relay and at least one of said other relays are closed.
Claim 3
Dependent Claim
19 words
The circuit of claim 1 including a relay coil shunted across said motor to operate said first relay means.
Claim 4
Dependent Claim
18 words
The circuit of claim 1 wherein said control circuit is in parallel with said power relay and motor.
Claim 5
Dependent Claim
24 words
The circuit of claim 1 wherein said environmental responsive relay means is a pressure operated relay sensitive to the output pressure of said compressor.
Claim 6
Dependent Claim
34 words
The circuit of claim 1 wherein said power relay is responsive to current in power relay control means, said power relay control means being in series in said control circuit with said relay means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |