4.0 Cooling Installation

4.1 Cooling Introduction

The Seakeeper 18 is shipped with the cooling circuit filled and ready for use. Only a confirmation of glycol level is required.

Reference Drawings

• 90667 – Seakeeper 18 Hardware Scope of Supply
• 90679 – Seakeeper 18 Cable Block Diagram
• 90540 – Seakeeper 16/18 Cooling Water Schematic
• TB-90947 – Seawater Plumbing Best Practices

The Seakeeper 18 is shipped with the cooling circuit filled and ready for use. The Seakeeper 18 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 18 heat exchanger is between 4 – 8 GPM (7.6 – 22.7 LPM) when the on-demand cooling system requires cooling. Prior to operation, confirmation of glycol level is recommended.

Seakeeper offers a compatible self-priming DC Seawater Pump (P/N 30332) prewired for the Seakeeper 18 Installation and covered under the standard Seakeeper warranty. The pump conforms to the seawater plumbing best practices noted in TB-90947. See Drawing No. 30332, Jabsco^® Seawater Pump Assembly, and the Seakeeper Options and Accessories Price List for details.

4.2 Installation Considerations

• The installer is responsible for supplying a dedicated positive-displacement seawater pump (or electric isolation valve and centrifugal pump) and associated plumbing. Seawater connections on the Seakeeper heat exchanger mate with ¾ in. (19 mm) hose. Seakeeper DC Seawater Pump, 24 VDC (P/N 30322), is an option from Seakeeper.
• Unintended seawater flow from the seawater pick-up during the vessel’s underway operation is unacceptable and may cause stress to internal components. Unintended flow should be mitigated through pump selection, using a diaphragm-style pump or an inlet control valve. Continuous cooling flow from shared through-hull plumbing, a centralized chiller, or a cooling system is unacceptable for on-demand Seakeeper models.
• Disconnecting the hose from the glycol pump is not necessary except to replace the pump. In this case, provision will need to be made to catch the glycol draining as the plumbing is disconnected. Use caution to avoid breaking plastic hose connections on the pump casing.
• The wire harness ‘Seawater Pump Out’ provides output to power and automatically control the seawater pump. This pump must operate on 24 VDC single phase and consume less than 10 A. Pumps requiring other voltages or higher current can still be controlled by using this supply from the motor drive to trigger an installer-supplied contactor, but a separate source of power must be provided.
• Maximum sea water pressure in heat exchanger is 20 psi (1.4 bar).
• Under all boat operating conditions, the minimum seawater flow requirement through the heat exchanger is 4 GPM (15.1 LPM), and the maximum is 8 GPM (30.3 LPM). When sizing the seawater pump, the installer should factor in losses for raw water plumbing. In addition to the initial operation at the dock, new installations should be checked to be within the flow requirements while the vessel is at speed. Flows above 8 GPM (30.3 LPM) could affect heat exchanger life.

4.3 Connecting Seawater to Heat Exchanger

1. Connect seawater from installer supplied pump to ¾ in. (19 mm) hose barb on heat exchanger. Use the same practices as typical below waterline seawater plumbing (See figure below).  Required flow rate is 4 GPM (15.1 LPM) minimum and 8 GPM (30.3 LPM) maximum.
2. Connect seawater return to overboard hull fitting.  Use the same practices as typical below waterline seawater plumbing.
3. In addition to initial operation at dock, new Seakeeper installations should be checked with a flow meter for minimum 4 GPM (16 LPM) flow while vessel is at speed and when backing down. 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.  A self-priming sea water 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.
   
   1. To prevent cavitation / aeration of the seawater intake a forward-facing scoop should be utilized. In addition, the seawater intake should be located in a location that will not aerate during normal underway operation.
4. Inspect raw water plumbing after sea trial for any signs of leakage.
5. Heat exchanger contains removable endcaps to provide access for cleaning the tube bundle.

Seakeeper Optional DC Seawater Pump (P/N 30322)

1. Seakeeper offers a self-priming DC Seawater pump as an optional addition, P/N 30322– DC Seawater Pump Assembly, shown in figure below.
2. The Seakeeper Seawater Pump is a 24 VDC pump.
3. The pump assembly is pre-wired for connection to Seakeeper 18 Seawater Pump Output Cable and includes a seawater strainer and various fittings. The pump specifications are as follows:

NOTE: Use only Jabsco^®-provided threaded fittings for DC Seawater Pump 30322.

4.4 Adding Coolant

1. Cooling system is filled to proper level when shipped, with a mixture of 50% ethylene glycol and 50% distilled water. Clear tube between thermostat housing and reservoir should be filled with green coolant mixture. 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 sea water connection in Connecting Seawater to Heat Exchanger section.

2. Mix 50% ethylene glycol with 50% distilled water in a clean container.  Refer to Table 1 or glycol manufacturer’s literature for freezing points.

3. Remove pressure cap on top of reservoir. Pour mixture in until level reaches top of clear tube between thermostatic valve and reservoir as shown in Figure 3.  Filling reservoir above this level will not cause any damage but coolant may be expelled from pressure relief port below cap due to normal thermal expansion of coolant.
4. Connect 24 V to controller.
   
   1. At the MFD app or 5″ Touch Display check for any ALARMS
   2. Press the POWER ON/OFF button .
   3. The flywheel will start to spin, and the glycol pump will start.
   4. Recheck glycol level with fluid circulating in coolant circuit. Look down inside reservoir and check that coolant level is above upper port on reservoir as shown in Figure 29.  Replace cap.
   5. After several minutes of running, press POWER ON/OFF button to turn power off to the flywheel and glycol pump. The glycol pump will stop, and the flywheel will coast to a stop.
   6. Seawater cooling is not required when the Seakeeper is powered off and the flywheel is coasting to a stop.
5. 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.