4.0 Cooling Installation

4.1 Cooling Installation Introduction

Reference Documents:

• 90377 – Seakeeper 3 Cable Block Diagram
• 90376 – Seakeeper 3 Cooling Water Schematic
• TB-90191 – Seawater Cooling Pump Recommendations
• 30331 – Seakeeper DC Seawater Pump Assembly

The Seakeeper 3 is shipped with the cooling circuit (shown in Figure 22) filled and ready for use. The Seakeeper 3 requires connection to a raw water pump, referred to as the seawater pump, to cool the closed loop cooling circuit on the unit. The required seawater flow through the Seakeeper 3 heat exchanger is between 2 – 6 GPM (7.6 – 22.7 LPM), under all vessel operating conditions. Prior to operation, confirmation of glycol level is required.

Seakeeper offers a compatible self-priming DC Seawater Pump (P/N 30331) that is prewired for the
Seakeeper 3 Installation and covered under the standard Seakeeper warranty. See Drawing No. 30331,
Seakeeper DC Seawater Pump Assembly for details and the Seakeeper Options and Accessories Price List for pricing information.

4.2 Installation Considerations

1. Installer is responsible for supplying a dedicated seawater pump and associated plumbing. Seawater connections on the Seakeeper heat exchanger mate with ¾ in. (19mm) hose. An optional seawater pump can be purchased through Seakeeper, P/N30331.
2. Seawater connections on the Seakeeper heat exchanger mate with 0.75 in. (19 mm) hose.
3. The seawater pump operates on 12 VDC with a max overcurrent protection rating of 15 A.
4. The seawater pump is powered by Seawater Pump Output Cable, via “SW Pump 12 VDC Out” connector on the Seakeeper 3, as outlined in Electrical Installation Section.
5. A dedicated through-hull fitting should be installed for each Seakeeper unit onboard the vessel to ensure sufficient seawater flow to each unit.
6. It is recommended that the seawater pump is located below the waterline, as close to the baseline of the vessel as practically possible, to maintain positive inlet pressure on the pump in all operating conditions.
7. A self-priming seawater pump may be required to maintain water flow in all underway conditions. Cavitation can occur at the seawater inlet and potentially cause an air-lock condition restricting seawater flow to the heat exchanger.
8. Maximum allowed seawater pressure in heat exchanger is 20 psi (1.4 bar).
9. Seawater flow requirement through heat exchanger is 2 GPM (7.6 LPM) minimum and 6 GPM (22.7 LPM) maximum under all operating conditions of the boat.
   
   When sizing seawater pump, installer should factor in losses for raw water plumbing. In addition to initial operation at dock, new Seakeeper installations should be checked to be within the flow requirements while vessel is at speed. Flows higher than 6 GPM (22.7 LPM) could affect heat exchanger life.
10. Vented loops (Figure 23) are optional and should only be considered with centrifugal style pumps. Self-priming or positive displacement style pumps do not require a vented loop, this includes Seakeeper P/N 30331.

4.3 Connecting Seawater to Heat Exchanger

Refer to Figure 23 for typical seawater plumbing arrangement.

1. Connect seawater pump to Seakeeper dedicated through-hull fitting. A strainer and seacock valve should generally be installed between the seawater inlet and the pump.
2. Connect seawater from installer-supplied pump to lower ¾ in. (19 mm) hose barb onheat exchanger. Use the same practices as other below waterline seawater plumbing.
3. Connect seawater discharge (upper hose barb) to overboard drain. Use the same practices as other below waterline seawater plumbing.
4. Required flow rate is 2 GPM (7.6 LPM) minimum and 6 GPM (22.7 LPM) maximum.
5. In addition to initial operation at dock, new Seakeeper installations should be checked for minimum 2 GPM (7.6 LPM) flow while vessel is at speed and when backing down.
   
   1. If no other method of confirming flow is available, discharge line may be temporarily diverted to a bucket. Flow is calculated from time to fill a known volume.
   2. A self-priming seawater pump (customer/installer supplied) may be required due to installation location to maintain water flow in all underway conditions where cavitation near the intake may occur and potentially cause an air-lock condition restricting seawater flow to the heat exchanger.
6. Inspect raw water plumbing after sea trial for any signs of leakage.

4.3.1 Seakeeper Optional DC Seawater Pump (P/N 30331)

1. Seakeeper offers a self-priming DC Seawater pump as an optional addition, P/N 30331– DC Seawater Pump Assembly, shown in Figure 24.
2. The Seakeeper Seawater Pump is a 24 VDC pump operated at 12 VDC for the Seakeeper 3 and maintains a seawater flow of approx. 2.5 GPM (9.5 LPM) at 12V DC.
3. The pump assembly is pre-wired for connection to Seakeeper 3 Seawater Pump Output Cable and includes a seawater strainer and various fittings. The pump specifications are as follows:

NOTE: Use only SeaFlo-provided threaded fittings for DC Seawater Pump 30331.

4.4 Adding Coolant

1. The Seakeeper 3 cooling system is filled to proper level when shipped. If level has dropped, check for evidence of leaks at all connections before adding fluid as described below. If coolant is at the correct level, skip to Step 5.
2. The minimum and maximum glycol levels are shown in Figure 25.

3. Mix 50% ethylene glycol with 50% distilled water in a clean container. Refer to Table 1or glycol manufacturer’s literature for freezing points.
   
   1. It is required that ethylene glycol with corrosion inhibitors be used. Most commercially available glycol has these additives standard.

4. Remove reservoir cap and pour mixture in until level reaches top face of the reservoir enclosure, as shown in Figure 25.
   
   1. Filling reservoir above this level will not cause any damage but coolant may be expelled from pressure relief port in cap due to normal thermal expansion of coolant.
5. Once the Seakeeper 3 and DC seawater pump are connected to 12 VDC power:
   
   1. At the MFD or Display check for any ALARMS.
   2. Cycle the Seakeeper 3 power, and Press the POWER ON button.
   3. The flywheel will start to spin and the glycol pump will start on demand.
   4. Recheck glycol level with fluid circulating in coolant circuit. Inspect reservoir to check coolant level is above minimum level of Figure 25. Replace cap if removed.
6. After several minutes of running, press POWER OFF button to turn power off to the Seakeeper.
7. The cooling system is self-purging. If small amounts of air are in the system, they will most likely be dislodged during the first sea trial. Recheck level after sea trial and add fluid if required.
   
   NOTE: It is not uncommon to see some air in the coolant system. It is normal and will not affect operation.