Installation: Hotstart OSE Heating System User Manual

Overview

The OSE Heating System is a preassembled oil-circulating heater for hazardous-location applications. It is designed for marine propulsion systems, diesel generator sets, locomotives, gas compressors, and other large engines that require oil temperature to be maintained while the engine or compressor is shut down.

The system combines an electric heating element, positive-displacement oil pump, temperature controls, protection devices, and a control enclosure on a steel mounting plate. Maintaining oil temperature helps preserve suitable oil viscosity and supports reliable equipment starting and lubrication.

Specifications

• Process-fluid temperature range: 0 °C to 80 °C.
• Ambient operating temperature: -20 °C to 40 °C.
• Available voltage range: 208 to 575 V AC.
• Power frequency: 50/60 Hz.
• Electrical configuration: single-phase or three-phase, depending on the model.
• Oil inlet connection: 0.5-inch or 0.75-inch NPT, depending on configuration.
• Oil outlet connection: 1.0-inch NPT on the illustrated system configuration.
• Control temperature adjustment range: 0 °C to 80 °C.
• Typical control temperature setting: 40 °C.
• Typical high-limit setting: 90 °C.
• Maximum pressure-relief setting for an external full-flow bypass application: 65 psi.
• Typical system certifications include Class I, Division 1, Group D, T3 and Class I, Zone 1, Group IIA, T3. Some configurations may use Class I, Division 2 or Class I, Zone 2 classifications.

Always use the identification plate on the individual OSE Heating System to confirm the exact model, voltage, frequency, current, phase, control-circuit voltage, serial number, and manufacturing year.

Detailed Description

During operation, the oil pump draws lubrication oil from the engine or compressor sump and sends it through the heating tank. Heated oil then returns through the lubrication circuit, allowing oil to circulate continuously throughout the connected equipment.

The control temperature relay monitors oil temperature through a resistance temperature device located at the heater inlet. The heating element cycles on and off to maintain the selected temperature. A separate high-limit temperature relay monitors the element area and stops the complete system if an excessive temperature is detected.

Important system parts include the prime button, Local/Off/Remote switch, reset button, pressure and temperature gauge, pressure-relief valve, oil inlet, pump motor, lifting points, oil outlet, heating element assembly, high-limit RTD, control RTD, identification plate, and heating tank.

The internal pump pressure-relief valve routes excessive discharge pressure back toward the pump suction side. Do not adjust this valve. If a lower downstream pressure is required, use a correctly specified full-bypass pressure-relief valve after the heating tank and route the bypass to the pump inlet.

Safety

• Disconnect electrical power and follow the site lockout and tagout procedure before wiring, servicing, cleaning, or opening an enclosure.
• In hazardous atmospheres, disconnect the equipment from the supply circuit before opening any enclosure, and keep enclosures closed during operation.
• Install conduit sealing fittings within 18 inches of the system enclosure where required by the installation classification.
• Electrical work must be completed by qualified personnel in accordance with applicable national, state, provincial, and local codes.
• Connect the system to a suitable protective earth and protect the supply with correctly sized overcurrent protection.
• Provide an accessible disconnecting means, preferably a circuit breaker or power switch near the heater.
• Hot surfaces may remain hot after power is removed. Avoid contact until the equipment and fluid have cooled.
• The pump and heater may start automatically or without warning. Use service-panel lockout before approaching moving or energized parts.
• Use the marked lifting points and suitable rigging. Never lift the system by conduit, cables, or cords.
• Do not repair damaged flameproof joints in the field.
• Maintain the cable bend radius established during factory wiring. For MC-HL cable, the minimum radius is seven times the cable outside diameter; for TC-ER-HL cable, it is four times the outside diameter.
• Never operate the heater without oil in the pump, lines, and heating tank. An empty system can damage the pump seal and may permit an explosive gas mixture to enter the tank.

Installation

Oil Plumbing

Keep the oil supply line as short and straight as practical. The supplied oil must have an unobstructed path to the pump, because excessive restriction can shorten pump-seal life and reduce circulation.

• Use a supply hose at least as large internally as the pump inlet. Do not reduce the line diameter.
• For the illustrated 0.5-inch NPT pump inlet, the recommended supply hose has a 1-inch inside diameter, a maximum length of 20 feet, and no more than four elbows.
• Each additional pair of 90-degree elbows reduces the recommended maximum line length by approximately 5 feet.
• Use sweeping bends or 45-degree fittings where possible.
• Install at least 6 inches of straight pipe immediately before the pump inlet.
• Install the oil suction port as low as practical in the sump, while avoiding areas where sediment or debris can enter.
• Install a customer-supplied swing-type or full-flow check valve close to the suction port to reduce reverse flow into the sump.
• Fill the supply line and its P-trap with oil before starting the pump.

Install a P-trap barrier in both supply and return lines. Each trap must drop below the engine or compressor oil-sump level and include at least a 5-inch drop and rise. This arrangement helps prevent a gaseous mixture from entering the heating system.

Size the return line at least as large internally as the pump outlet. For diesel engines, route the return to the discharge port at the opposite end of the oil sump. Compressor installations may use the opposite end of the sump or a prelube location. When a small or medium compressor uses a prelube return location, install a bypass to the sump with a tee and a full-flow pressure-relief valve set no higher than 65 psi.

Mounting

• Mount the heater horizontally with the pump and motor above the heating tank.
• Position the tank so it remains completely full of oil while operating.
• Mount the system at or below the minimum oil level when practical. If the pump is above that level, install a check valve.
• Keep the heater isolated from engine vibration. Do not mount it directly to the engine.
• If rigid piping is used, include flexible hose sections at the supply and return connections.
• Provide at least 18 inches of clearance for removal of the heating element.
• Follow the mounting orientation shown on the system drawings. Do not install the unit at an angle or in another orientation.

Electrical Connections

Connect the specified customer-supplied power to the main terminal block inside the control box. The source voltage must remain within plus or minus 10 percent of the rating shown on the identification plate.

• Three-phase systems use terminals marked L1, L2, and L3.
• Single-phase systems use terminals marked L1 and L2 or L and N, as identified on the unit.
• Connect the main grounding conductor to the ground block.
• Use metallic conduit or armored cable as required for the hazardous-location installation.
• Use conductors and grounding methods that comply with the applicable electrical code and the system markings.

Customer Interface

• Remote On/Off: A 24 V DC shutdown input stops the heating system when activated. The factory wiring is normally closed unless changed according to the system schematic.
• Fault signal: Indicates shutdown caused by the high-limit temperature relay or motor protection switch.
• Motor run signal: Indicates that the pump motor is operating.

Three-Phase Motor Rotation

Check pump rotation on three-phase systems before introducing oil to the pump. Briefly energize the motor and compare fan rotation with the direction shown on the motor decal. If rotation is incorrect, disconnect power and interchange any two incoming phase leads at the main terminal block, then repeat the check.

Do not run the pump dry for more than a few seconds. Single-phase systems are factory wired for the correct rotation and do not require this check.

Setup and Operation

Controls

• Prime button: Operates the pump without energizing the heating element, allowing trapped air to be removed from the supply and return lines.
• Local: Starts the system from the local controls.
• Off: Stops the system and is required before resetting the motor protection switch.
• Remote: Allows operation through the connected remote-control circuit.
• Reset button: Resets a motor protection fault after the Local/Off/Remote switch has been placed in Off.
• Pressure gauge: Shows a pressure increase when the pump is priming or circulating oil. Normal pressure varies with the connected equipment and plumbing.

First Start-Up

1. Complete the three-phase motor-rotation check before filling or operating the pump, when applicable.
2. Inspect and tighten all electrical and plumbing connections.
3. Open the isolation valves.
4. Confirm that the heating tank, pump, supply line, return line, and P-traps contain oil.
5. Open a plug or fitting near the pump to release trapped air safely.
6. Press and hold the prime button until air is removed and the pressure gauge shows an increase.
7. Place the Local/Off/Remote switch in Local.
8. Observe the system for leaks, abnormal noise, stable pressure, and proper circulation.
9. Set the control relay to the required operating temperature. The recommended control setting is 40 °C.
10. Set the high-limit relay at least 10 °C above the control setting. The typical high-limit setting is 90 °C.
11. Place the switch in Remote and verify that the remote shutdown, fault, and motor-run signals operate correctly.

The OSE Heating System should be turned off when the engine or compressor starts. It is intended to maintain oil temperature while the driven equipment is shut down, not to operate simultaneously with the engine or compressor unless the application specifically requires that arrangement.

Cleaning and Maintenance

Routine Maintenance

• At initial start-up, tighten electrical connections.
• After one week of operation, inspect and retighten electrical connections.
• Every three months, tighten electrical connections and check for signs of heat or looseness.
• Annually, drain, clean, and flush the heating system.
• During annual service, inspect hoses for cracks or weakening, examine wiring for wear or excessive heat, and tighten mounting bolts.
• Replace magnetic contactors approximately every five years.
• Replace the volatile corrosion inhibitor inside the control box once each year.

Inspection Guidance

Inspect plumbing connections for leaks. A loose suction-side connection can allow air into the heating tank, cause cavitation, reduce flow, and damage the heating element. Check mounting bolts because vibration can loosen them over time.

The pump pressure-relief valve and pressure gauge do not require routine adjustment or maintenance. Do not alter the internal pump relief setting, because modification can compromise the system and void the applicable warranty.

Inspect magnetic contactors for welded contacts, arc erosion, mechanical wear, or a failed coil. A continuity check across the coil can identify an open or shorted coil, but electrical testing must be performed by qualified personnel with the system de-energized.

Temperature-Control Troubleshooting

If the system fails to maintain its selected temperature or immediately reports a high-limit fault, first de-energize the system, verify that oil is present and unrestricted, and confirm that the tank fluid is below 50 °C.

• Confirm that the control relay setting is correct.
• Confirm that the high-limit setting is at least 10 °C above the control setting.
• Using an ohmmeter, check the specified TCR terminals. A resistance between 80 and 120 ohms permits further testing.
• Check continuity between the designated TCR terminals. If continuity is present, the relay, RTD, and cable are generally functioning correctly.
• If the TCR reading is outside 80 to 120 ohms, investigate the relay or connected temperature-sensing circuit.
• Test the RTD between pins 1 and 3 for 80 to 120 ohms and check continuity between pins 1 and 4.
• Replace the RTD cable if the RTD tests correctly but the cable circuit does not.
• Replace the RTD if its resistance or continuity is outside the specified results.

Storage

• Do not store the heating system full of oil. Thermal expansion can cause oil to seep past the pump seals.
• If oil seeps during storage, clean the area thoroughly, including the space between the pump and motor, and test the pump after cleaning.
• For long-term storage, keep plugs and caps tight and protect the unit from rain and directed spray.
• For storage longer than three months, place desiccant bags beside the system when it remains in its original packaging and inside the control box.
• For storage of one year or longer, replace the control-box volatile corrosion inhibitor every six months.
• A motor stored for a year or longer may require lubrication before first use if it has provisions for relubrication. Follow the lubrication information on the motor nameplate.

Troubleshooting

Oil Temperature Is Too High

• Pump not primed: Bleed trapped air from the lines and restart the system.
• Isolation valve closed: Open the valve and restart.
• Kinked or crushed hose: Remove the restriction and restart.
• Suction-line leak: Repair the leak and reprime the system.
• Incorrect three-phase rotation: Interchange two incoming power leads, then restart.
• Control relay failure: Test and replace the relay if necessary.
• Motor or contactor failure: Test the affected component and replace it when required.
• Motor protection switch tripped: Reset it. If it trips again, investigate the motor and pump.

Oil Temperature Is Too Low

• Motor failure: Test the motor and replace it if required.
• System recently switched on: Allow sufficient time for the circulating oil to reach temperature.
• Heating element failure: Check element continuity and replace the element if necessary.
• Element fuse or breaker problem: Test the element fuses, replace failed fuses, and reset a tripped breaker.
• Element contactor failure: Check the contactor coil and contacts, then replace the contactor if needed.
• Motor contactor failure: Check the coil and contacts and replace the contactor when required.
• Control relay failure: Test the relay and replace it if necessary.

System Fault Shutdown

A high-temperature condition causes the high-limit relay to stop both the heating element and pump motor. To restart, move the Local/Off/Remote switch to Off and then return it to Local or Remote after the cause has been corrected.

If the motor protection switch trips, place the switch in Off, press the reset button, and return the selector to the required operating mode. Repeated trips indicate an unresolved motor, pump, wiring, or flow problem that requires qualified service.

Pros & Cons

• Pros: Prewired and preplumbed construction simplifies integration; continuous oil circulation supports engine or compressor lubrication; adjustable temperature control maintains the selected oil temperature; hazardous-location configurations include dedicated protection and monitoring circuits; remote shutdown, fault, and motor-run interfaces support automation.
• Cons: Installation requires careful oil-line sizing, priming, P-trap placement, vibration isolation, grounding, and hazardous-location compliance; the system must never run dry; maintenance requires periodic electrical inspections, annual fluid-system service, and qualified troubleshooting of temperature and motor circuits.