**Device Type:** Analog Output - Actuator

**Signal:** 0-10VDC / 2-10VDC / 4-20mA input

**Power:** 24VAC (most common) / 24VDC / 120VAC

**Version:** 1.0 | **Date:** Dec 2025

---

**Common Models:**

- Belimo LRB24, NRB24, TRB24, Johnson Controls VA-7000, Honeywell ML6420/ML7420, Siemens SKC/SKD

**Used For:**

Chilled water valves, hot water valves, condenser water valves, steam valves, glycol loops

- **Force:** 90-500 lbs (match to valve size)

- **Stroke:** 1/2" to 2" typical

- **Stroke Time:** 30-180 seconds typical

- **Fail Mode:** Spring return (SR) or non-spring (NSR)

- **Wire Type:** 18AWG minimum for control, 16AWG for power

- **Wiring:** 3-wire (power, common, control) or 4-wire (+ position feedback)

**Environment:** 32°F to 125°F ambient, valve body may be hotter

---

- ☑ Safety glasses (ANSI Z87.1)

- ☑ Heat-resistant gloves (pipes may be hot - up to 200°F)

- ☑ Hard hat (mechanical rooms)

- ☑ Face shield (if system under pressure)

- ⚠ **HOT SURFACES** - Hot water pipes (up to 200°F), steam pipes (up to 250°F+)

- ⚠ **COLD SURFACES** - Chilled water pipes (35-45°F) - risk of cold burns with prolonged contact

- ⚠ **PRESSURIZED SYSTEMS** - Water systems under 30-150 PSI

- ⚠ **PINCH POINTS** - Valve stem moves with force

- ⚠ **CHEMICAL EXPOSURE** - Glycol, water treatment chemicals (if leak occurs)

- [ ] **NOT typically required** for actuator replacement (if valve can stay in place)

- [ ] **REQUIRED if removing valve:** Coordinate with building operator

- [ ] Close isolation valves upstream and downstream

- [ ] Drain/depressurize section of piping

- [ ] Keep drain bucket ready in case of residual water

---

- Adjustable wrenches (two - for coupling nuts)

- Allen wrenches (actuator mounting)

- Wire strippers (18-16 AWG)

- Multimeter (DMM)

- Label maker

- Teflon tape or pipe dope (if removing valve)

- Bucket/rags (for water drainage)

- Coupling hardware (included with actuator)

- Wire nuts or terminal blocks

- Cable ties

- Mounting bracket (if needed)

- [ ] Verify actuator force rating matches valve size

- [ ] Confirm actuator stroke length matches valve stem travel

- [ ] Check control signal type matches actuator input

- [ ] Verify fail-safe requirement (spring return vs non-spring)

- [ ] Verify valve accessible and piping supported

- [ ] Note current valve position (for reference)

1. **Remove old actuator** (if replacement):

- Manually position valve mid-stroke (ease spring tension)

- Disconnect wiring, label if reusing

- Remove coupling from valve stem

- Remove actuator from mounting bracket

- **CAUTION:** Spring return actuators have spring tension - control release

2. **Inspect valve stem:**

- Check stem clean, no corrosion or damage

- Verify stem moves freely (manually push/pull)

- If seized: Valve needs service before actuator install

- Check packing gland not leaking

3. **Mount actuator:**

- Position actuator on mounting bracket (yoke)

- Align actuator shaft with valve stem

- Install coupling per manufacturer:

* Direct couple: Thread onto stem or use clamp

* Universal joint: Connect both ends

- Verify actuator cannot slide off stem

4. **Set stroke limits** (if adjustable):

- Manually position valve to full closed

- Adjust actuator closed stop (if available)

- Manually position valve to full open

- Adjust actuator open stop

- Verify stroke length matches valve travel (1/2" to 2" typical)

5. **Route and terminate wiring:**

* Red: +24VAC/VDC power

* Black/Blue: Common

* White/Green: Control signal (0-10V / 2-10V / 4-20mA)

* Add Yellow/Orange: Position feedback signal

- Tighten terminals: 7-9 in-lbs

- Support wire away from hot pipes with cable ties

- Leave 12" service loop

6. **Label wiring:**

- Example: "AHU-1-CHWV" (AHU-1 Chilled Water Valve)

- Label both ends clearly

- [ ] Actuator mounted securely on valve

- [ ] Coupling tight on valve stem (no slipping)

- [ ] All wires terminated tight (7-9 in-lbs)

- [ ] Labels applied both ends

- [ ] Stroke limits set correctly

- [ ] No water leaks at packing gland

- [ ] Wiring routed away from hot surfaces

- [ ] Work area cleaned

- [ ] Photos taken

---

- **Continuity:** Each wire <5 ohms end-to-end

- **Isolation:** >10K ohms to ground

- **Valve Movement:** Stem moves freely by hand, no binding

- **Spring Return Test:** If SR model, valve returns to fail-safe position when actuator removed

- **Supply Voltage:** 24VAC/VDC ±10% (21.6-26.4V) or 120VAC ±10%

- **Power Consumption:** 3-8 VA (24V) or 10-15 VA (120V) typical

* 0-10VDC: 0V = closed, 10V = open

* 2-10VDC: 2V = closed, 10V = open

* 4-20mA: 4mA = closed, 20mA = open

| Control Signal | Expected Position | Feedback Signal |

|---------------|-------------------|-----------------|

| 0V / 2V / 4mA | 0% (Closed) | 0V / 2V |

| 5V / 6V / 12mA | 50% (Half-open) | 5V / 6V |

| 10V / 10V / 20mA | 100% (Open) | 10V / 10V |

**Stroke Time:** 30-180 seconds full travel (depends on model)

---

- **Do:** Engage manual override lever on actuator

- **Expect:** Actuator can be manually positioned, motor disengaged

- **Pass If:** Manual override works, returns to auto when released

- **Do:** Command actuator from controller: 0% → 100% → 0%

* Smooth, continuous movement (no jerking)

* Stroke time within spec (30-180 sec)

* Position indicator moves smoothly

* Valve stem moves full travel distance

- **Pass If:** Completes full stroke both directions within spec time

- **Do:** Command 0%, 25%, 50%, 75%, 100%

- **Expect:** Actuator stops at each position, feedback matches command

- **Pass If:** Position within ±5% of commanded

- **Do:** Stroke valve while observing:

* Supply/return temperature differential (ΔT)

* Flow meter reading (if available)

* Coil performance (heating/cooling output)

* 0% position: Minimum flow, maximum ΔT

* 100% position: Maximum flow, minimum ΔT

* Gradual change between positions

- **Pass If:** Flow control is proportional to valve position

- **Do:** Remove power while actuator at mid-position

- **Expect:** Actuator returns to fail-safe position:

* Cooling valves: Typically close (NC)

* Heating valves: May close or open depending on application

- **Pass If:** Returns to fail-safe within 30 seconds, stays in position

- **Do:** Observe valve packing gland during full stroke

- **Expect:** No water dripping from stem

- **Pass If:** Packing gland remains dry through full operation

- [ ] Actuator appears in controller output list

- [ ] Controller can command actuator (0-100%)

- [ ] Position feedback reads correctly (if equipped)

- [ ] Graphics show live position

- [ ] Actuator responds to PID loop control

- [ ] No faults or errors

---

1. Measure supply voltage at actuator: 24VAC/VDC or 120VAC ±10%

2. Test continuity of power wiring end-to-end: <5 ohms

3. Check terminal connections tight

4. Verify polarity (DC circuits)

5. Listen for motor sound when commanded (should hear humming)

6. **If voltage present but no sound:** Replace actuator (motor failed)

1. **Check coupling:** May have loosened or stripped

2. **Manually try to move stem:** Should feel resistance from actuator

3. **Check valve stem:** May be seized or broken

4. **If coupling loose:** Tighten or replace

5. **If stem seized:** Valve needs service/rebuild

6. **If stem broken:** Valve replacement required

1. Verify control signal at actuator terminals

2. **If signal correct but position wrong:** Check stroke limits

3. Adjust stroke limits to match valve travel

4. Verify coupling not slipping on stem

5. Check position feedback wiring (if equipped)

6. **If feedback wrong:** Check feedback wire, verify at controller

1. Check valve for physical problems:

- Stem bent or damaged

- Internal valve parts seized or broken

- Packing gland too tight

2. Measure current draw: >300mA indicates overload

3. **If overcurrent:** Valve too large for actuator or valve needs service

4. **If binding specific position:** Adjust stroke limits

5. **If generally binding:** Service valve or replace actuator with higher force

1. Measure supply voltage under load: Should stay ±10%

2. Check for voltage drop in long wire runs

3. Verify control signal stable

4. Listen for motor sounds (grinding indicates wear)

5. **If voltage drops:** Increase wire gauge

6. **If motor sounds bad:** Replace actuator (gearbox failing)

1. **NOT an actuator issue** - packing gland needs adjustment

2. Slightly tighten packing nut (1/4 turn at a time)

3. **If still leaking:** Packing needs replacement (coordinate with plumber)

4. **CAUTION:** Over-tightening can bind valve stem

1. **NOT typically actuator issue** - valve seat worn or damaged

2. Verify actuator reaching full closed position (0% command)

3. If actuator at 0% but water still flowing: Valve needs service/replacement

4. **Temporary workaround:** Slightly over-close using controller offset (if available)

1. Remove power and manually feel spring tension

2. **If no spring:** Spring broken - replace actuator

3. **If valve won't move:** Valve may be too tight for spring force

4. Check for valve binding preventing spring return

---

- [ ] Verified supply voltage at actuator (24V or 120V ±10%)

- [ ] Verified control signal at actuator terminals

- [ ] Checked coupling tight on valve stem

- [ ] Tested actuator manually (override if equipped)

- [ ] Observed valve stem movement through full stroke

- [ ] Checked for valve binding or stem damage

- [ ] Verified no water leaks at packing gland

- [ ] Documented actual stroke time

- [ ] Taken photos of installation

- [ ] Reviewed actuator installation manual

- **Actuator:** [Mfg / Model / Force Rating / Location]

- **Valve:** [Type / Size / Normally Open or Closed]

- **Application:** Chilled water / Hot water / Steam / Condenser water

- **Supply Voltage:** _____ VAC/VDC

- **Control Signal:** 0-10V / 2-10V / 4-20mA

- **Commanded Position:** _____ %

- **Actual Position:** _____ % (visual or feedback)

- **Stroke Time:** _____ seconds (0-100%)

- **Water Temperature:** _____ °F (supply and return)

- **ΔT:** _____ °F (supply - return)

- **Symptoms:** [Not moving, slow, binding, leaking, etc.]

- **Steps Taken:** [Troubleshooting completed]

- **Photos:** Attached

- **Field Specialist:** [Phone]

- **Programmer:** [Phone] (if PID loop tuning issue)

- **Project Manager:** [Phone] (if wrong actuator size)

- **Dispatch:** [Phone]

---

✓ **Actuator sizing:** 90-150 lbs for 2-way valves up to 2", 200-500 lbs for larger or 3-way valves

✓ **Spring return vs non-spring:** SR for fail-safe (cooling valves close on power loss)

✓ **Normally Open vs Normally Closed valve:** Must match application (NC for cooling typical)

✓ **2-10V vs 0-10V:** 2-10V preferred - provides broken wire detection

✓ **Stroke time:** Longer stroke time (90-180 sec) prevents water hammer

✓ **Hot pipes:** Route wiring away from pipes >140°F to prevent insulation damage

✓ **Valve cycling:** Excessive cycling (>6 per hour) indicates PID loop needs tuning

✓ **Position feedback:** Essential for accurate control - use 4-wire actuator

✓ **Packing gland:** Light leak from packing is normal, but excessive leak needs adjustment

✓ **Manual override:** Use during commissioning to verify valve operation

✓ **Glycol systems:** More viscous than water, may require longer stroke time

---

**Document ID:** SSO-VALVE-001

**Revision:** 1.0

**Next Review:** Dec 2026