Overview
This field reference covers retrofitting a 60-gallon upright SpeedAire 220V single-phase reciprocating compressor with a fully automatic tank drain that only fires when the motor is actually running. The intent is to dump condensate every time the pressure switch closes and the contactor pulls in, without depending on a separate 120V receptacle, without energizing the solenoid continuously, and without any modification to the motor branch circuit beyond parallel wiring of a single timing relay.
The build uses three components: an Asco RED HAT 8262H202 normally-closed 1/4" NPT solenoid valve (220/50V coil), an Omron H3Y-2 power-on delay time-delay relay (DPDT, 0.2 to 5.0 second range), and a small piece of 1/4" NPT brass piping. The end result is a one-second (or longer, see Manual Override) blow-down of the tank sump every time the motor cycles on.
Bill of Materials
| Item | Manufacturer / Part | Spec / Function |
|---|---|---|
| Solenoid valve | Asco RED HAT 8262H202 | 1/4" NPT, NC, brass body, 220/50V, Cv 0.20 |
| Time-delay relay | Omron H3Y-2 (200/220/230/240 VAC coil) | Power-on delay, DPDT, 0.2–5.0 s, 8-pin octal |
| Drain piping | 1/4" NPT brass nipple + 90° elbow | Adapts tank drain port to solenoid inlet |
| Enclosure | Customer-supplied NEMA 1 or better | Houses TDR and wiring landings |
| Override pushbutton (optional) | Grayhill 4000 series momentary N/O | Manual drain, wired in parallel with TDR NO contact |
Component Specifications
Asco 8262H202 Solenoid Valve
| Parameter | Value |
|---|---|
| Valve function | 2-way, normally closed (energize to close) |
| Port size | 1/4" NPT |
| Orifice | 3/64" (1.2 mm) – 1/8" depending on body code |
| Cv (typical) | 0.20 |
| Operating pressure differential | 0 to 150 psi (air/inert gas) |
| Maximum fluid temperature | 180 °F (82 °C) |
| Coil voltage (this build) | 220/50 V, 50/60 Hz |
| Coil insulation class | F (155 °C) |
| Lead wires | Two red (line) + green/yellow (ground) |
| Body material | Brass |
The valve is field-rebuildable: the solenoid coil, plunger, and spring can be replaced without removing the valve body from the line. The 8262H series is listed for general-purpose compressed air service, and the 150 psi differential rating is well above the typical 135–150 psi cut-out of a 60-gallon residential/light-commercial receiver.
Omron H3Y-2 Time-Delay Relay
| Parameter | Value |
|---|---|
| Operating mode | Power-on delay (delay on make) |
| Time range | 0.2 to 5.0 seconds (this build: 1.0 s) |
| Contact form | DPDT (2 Form C) |
| Contact rating (resistive) | 5 A at 250 VAC, 5 A at 30 VDC |
| Coil voltages available | 24, 100/110/120, 200/220/230/240 VAC; 12, 24, 100/110, 125, 200/220 VDC |
| Mechanical life | 10,000,000 operations |
| Electrical life (rated load) | 200,000 operations |
| Repeat accuracy | ±1 % FS (max) |
| Setting accuracy | ±10 % FS (max) |
| Reset time | 0.1 s max |
| Power consumption | 2 VA (240 VAC) / 1.2 W (240 VDC) |
| Mounting | 8-pin octal socket (PF085A) or panel mount |
H3Y-2 Terminal Map (8-Pin Octal Base, Bottom View)
| Pin | Function | Use in this build |
|---|---|---|
| 2 | Coil L1 | 240 VAC hot (in parallel with contactor coil L1) |
| 10 | Coil L2 (neutral) | 240 VAC other line (in parallel with contactor coil L2) |
| 1 | NC contact common (group A) | Jumpered to pin 2 (coil L1) |
| 9 | NC contact A | Solenoid L1 wire |
| 5 | NO contact A | Optional 240 VAC switched leg (for alternate hookups) |
| 4 | NC contact common (group B) | Spare (or pushbutton return) |
| 12 | NC contact B | Spare (or pushbutton return) |
| 8 | NO contact B | Spare (or pushbutton NO output) |
Circuit Design Principles
The fundamental requirement is that the solenoid must be energized (valve closed, holding tank pressure) the entire time the compressor is idle, and de-energized (valve open, dumping condensate) only when the motor is running. This guarantees three things:
- If power to the shop is lost, the valve fails safe and dumps the tank (NC valve + no coil power = open).
- The valve is never left open while the compressor is sitting idle, so a leak cannot slowly depressurize the receiver.
- The drain cycle is automatic and synchronized with motor run time, so the user does not have to remember to drain.
To meet these requirements, the TDR coil must be wired so that it only sees 220/240 VAC when the contactor coil is energized. The cleanest way to do this on a SpeedAire-style 220V magnetic starter is to land the H3Y-2 coil in parallel with the contactor coil, using the two control-circuit landings already provided by the pressure switch.
Correct Wiring Configuration
The wiring below is the configuration that works. It uses the normally-closed contact set (pins 1 and 9) of the H3Y-2, with a short jumper from the coil hot (pin 2) to the NC common (pin 1) so that the solenoid is normally energized and then released for the duration of the delay window.
Step-by-Step Wiring
- Verify the supply. With the compressor unplugged, identify the two control-circuit landings at the pressure switch. On a SpeedAire 60-gallon unit these are the "line" side of the switch where 220/240 VAC is present at all times when the cord is plugged in.
- Land the TDR coil in parallel with the contactor coil. Run one conductor from the L1 control landing to pin 2 of the H3Y-2 octal socket, and one from the L2 control landing to pin 10. The TDR will now energize exactly when the contactor pulls in.
- Jumper pin 2 to pin 1 with a short piece of insulated #18 AWG (or whatever gauge the rest of the harness uses). This puts pin 1 at the same potential as the L1 side of the coil.
- Wire the solenoid. Connect one solenoid lead (red, not the green ground) to pin 9 of the octal socket. Connect the other solenoid lead to pin 10 (L2). The green/yellow ground lead from the solenoid should land on the equipment grounding conductor or on the enclosure grounding lug.
- Set the timing. With power off, adjust the H3Y-2 dial to 1.0 second. The dial is on the top of the unit; full scale is 5.0 s.
- Power up and test. With the tank bled down below cut-in, plug in the compressor. The contactor should pull in, the H3Y-2 should start timing (LED on), and after one second the solenoid should click off (NC valve opens). You should hear a short burst of air exhausting from the drain.
Why the Initial Wiring Failed
The most common failure mode is feeding the TDR coil from the "always hot" side of the pressure switch (i.e., upstream of the switch contacts) rather than from the contactor coil landings. If the TDR is hot whenever the compressor is plugged in, the NC contact 1–9 is open continuously, the solenoid never sees 220/240 VAC across it, and the valve remains in its mechanical-fail-safe closed position – no drain ever occurs, and the tank never loses pressure because the valve is closed, not because the drain worked.
Symptom: TDR "time up" LED illuminates as expected, but the solenoid does not click. The solenoid is mechanically fine (verify with a bench test on 220 VAC). Cause: the TDR output is wired to a line that is only energized when the TDR itself is de-energized – a self-defeating feedback loop.
Adding a Manual Override Pushbutton
For an extended manual blow-down (e.g., 20 seconds after a long run, or to clear a freeze-up), a normally-open momentary pushbutton can be wired in parallel with the NO contact set of the TDR (pins 4 and 8, or pins 5 and 9, depending on which group you leave free for the auto-drain function).
- Move the solenoid "L1" lead from pin 9 to pin 5 (NO contact).
- Add a short jumper from pin 1 (NC common, which is already at L1 via the existing 2→1 jumper) to pin 5 (NO common). This is a wiring change from the auto-only version – the NC contact is no longer carrying the solenoid; the NO contact is.
- Land one side of the N/O pushbutton to the same point as the solenoid L1 lead. Land the other side of the pushbutton to pin 9. When the button is pressed, pins 9 and 1 are tied together through the button and the existing 1→2 jumper, energizing the solenoid.
- The TDR's NO contact (pin 5) is now in parallel with the pushbutton. When the TDR times out, the NO contact closes and the solenoid is energized (valve closed) for the remainder of the motor run.
The Grayhill 4000 series momentary pushbutton is a common industrial-grade choice. The optional button-guard accessory prevents accidental actuation; a 1.5–2.5 A contact rating is more than sufficient for a 0.5 A inductive solenoid load.
Verification and Commissioning
| Check | Expected result |
|---|---|
| With compressor idle, solenoid click | Single audible click on plug-in (or none, if it was already latched); valve mechanically closed |
| Pressure gauge with compressor off | Stable for 10 minutes; no slow leak through drain |
| Pressure switch cut-in (typical 120 psi) | Motor starts, contactor pulls in, TDR LED on, 1 s later solenoid clicks off, brief exhaust at drain |
| Pressure switch cut-out (typical 135 psi) | Motor stops, TDR de-energizes, solenoid re-energizes (clicks on), drain closes |
| Manual pushbutton (if installed) | Holding button holds valve open; releasing closes it |
| Loss of shop power | Solenoid de-energizes, valve opens, tank vents to atmosphere (fail-safe) |
Troubleshooting Matrix
| Symptom | Likely cause | Corrective action |
|---|---|---|
| Solenoid never clicks, TDR LED never lights | No power to TDR coil; wrong pinout (2/10 are coil) | Re-verify coil lands; 220/240 VAC must be across pins 2 and 10 when contactor is energized |
| Solenoid never clicks, TDR LED lights after 1 s | TDR is on the wrong side of the pressure switch (always hot), NC contact is open continuously | Re-wire TDR coil in parallel with the contactor coil, not upstream of the pressure switch |
| Solenoid clicks on but never off | NO contact wired instead of NC; or TDR is power-off delay instead of power-on delay | Confirm H3Y-2 mode (label: "T" style is power-on delay); move solenoid lead from pin 5 to pin 9 (NC) |
| Solenoid chatters / rapid clicking | Insufficient coil voltage; high-resistance splice | Check voltage across solenoid while running; re-land any backstab or wire-nut splices |
| Drain stays open with compressor off | Wired to NO contact and the contact is closed at rest (wrong model variant) | Verify contact form on the timer body label; H3Y-2 is power-on delay with NC at rest |
| Tank loses pressure overnight | Foreign material holding solenoid plunger open; or valve installed in reverse | Disassemble and clean solenoid; verify flow direction arrow |
| Compressor short-cycles, never builds pressure | Drain never closes (stuck open solenoid) or excessive drain flow | Inspect solenoid, verify NC function with bench test |
Safety Considerations
- Work on this retrofit with the compressor unplugged and the tank fully bled to 0 psi. A charged 60-gallon tank at 135 psi stores approximately 52,000 ft·lbf of energy, enough to drive a projectile through a cinder block.
- The Asco 8262H202 has a maximum fluid temperature of 180 °F (82 °C). Reciprocating compressor discharge can run 200–350 °F at the head, but the tank sump is well below this in a 60-gallon vertical receiver; the limit is rarely an issue in practice but should be verified if the compressor is in an unusually hot environment or runs continuously.
- The green/yellow ground lead from the solenoid must be landed. Do not rely on the brass pipe thread to provide a chassis ground; dielectric grease on the threads and a NBR or EPDM seal can isolate the valve body from the tank.
- The TDR coil and the solenoid coil are both continuous-duty; this design intentionally has the solenoid energized the entire time the compressor is idle. As long as the valve is sized for continuous duty (the 8262H is), coil life is the limit – typically 100,000+ hours. Use a nameplate coil, not a generic 220V coil, if you ever replace it.
- Confirm that the contactor coil rating matches the TDR coil rating (both 200/220/230/240 VAC for the H3Y-2, both 220/50 Hz for the 8262H202). A 240 V TDR coil on a 220 V circuit will work but pulls more current; a 110 V TDR coil will burn out in seconds on 220 V.
Spare-Parts and Life-Cycle Notes
The 8262H202 solenoid plunger and spring kit (Asco part number prefix 30204- for the H series) is the only field-replaceable wear item. The H3Y-2 timer is fully solid-state with no serviceable parts; if it fails, replace the entire timer. Both components are stocked at most industrial supply houses and ship quickly.
Why is the Asco 8262H202 specified as a normally-closed valve?
A normally-closed valve is fail-safe: if the coil loses power (shop power outage, TDR failure, wire break), the valve opens and dumps the tank. This is the safe direction for compressed air – a stuck-open drain leaks slowly, a stuck-closed drain means the user drains manually but the system still works. Asco 8262-series valves are also bidirectional and tolerant of contaminated condensate, which is what a compressor sump produces.
Can I substitute a 120V solenoid and power the timer from a wall outlet?
Yes, but the build loses two key properties: (1) the drain will not fire automatically with the compressor cycle – it requires the wall outlet to be on a switched circuit, and (2) the drain will not fire during a power outage, leaving the tank full. Wiring the timer across the contactor coil as shown gives you automatic, loss-of-power safe behavior with no 120V branch circuit required.
What drain time should I set on the H3Y-2?
One second is a good starting point for a 60-gallon residential/light-commercial receiver. The dump actually lasts for the entire motor run time after the 1-second delay, because the NC contact remains open until the TDR de-energizes. For a 60-gallon unit cycling on for 30–60 seconds, you will get 29–59 seconds of blow-down per cycle, which is far more than the minimum 3–5 seconds typically recommended to clear condensate.
Does this modification affect the compressor warranty?
No internal parts of the compressor pump, motor, contactor, or pressure switch are modified. The timer and solenoid are wired in parallel with the contactor coil and the drain port only – both are non-invasive connections. Document the wiring with a schematic inside the enclosure and keep the original wiring diagram taped to the inside of the compressor cabinet for any future service.
My compressor is 3-phase, not single-phase 220V. Does the wiring change?
Yes – a 3-phase unit has a 3-pole contactor and three line voltages to the motor. The TDR coil must be wired across any two of the three phases (matching the contactor coil voltage), and the solenoid must be rated for the line-to-line voltage of those two phases. Use the contactor coil landings as the reference; the TDR coil and the contactor coil must see the same voltage. The logic and pinout of the H3Y-2 are otherwise identical.