The purpose of a high water alarm is to notify you if the something is wrong and the sewage pump is not working so you can stop using the bathroom before the sewage basin overflows. The pump could stop working due to:

• A power outage
• The circuit breaker has tripped
• The discharge line is clogged
• The check valve is malfunctioning
• The ball valve is inadvertently closed, stopping the flow

I bought a Zoeller A-PAK FM0483 high water alarm that is rated for sewage basin applications. The Zoeller alarm is extremely loud and features a 9 volt battery backup in a addition to 120VAC primary power. The A-PAK alarm kit is shown below.

Zoeller A-PAK ALARM - Part # FM0483

Alarm Switch Installation

Installation was straightforward following the Zoeller instruction sheet. I located the alarm switch such that it would trigger when the water level reached the inlet pipe given the capacity of the 3/4 HP pump to “stay ahead” of the maximum inflow rate from the bathroom. Click on the photo below for a larger image. (The evaporation rings inside the basin are from mud and rain water that entered during construction of the home.)

Sewage Pump with High Water Alarm

The wiring leads through the sewage basin cover are:

• High water alarm signal wire – coiled
• Sewage pump power
• Sewage pump on/off switch

Sewage Basin Wiring

Alarm Panel Installation

The alarm panel should be powered by a different 120VAC electrical circuit from that of the sewage pump. The reason for this is so the alarm panel remains powered up if the circuit breaker serving the pump is tripped. I therefore need to install a new electrical outlet on a different circuit from that of the pump.

Fortunately I had ready access to a electrical junction box that I installed for the florescent light in the plumbing closet. It was a simple task to locate a new electrical outlet box and wire a duplex receptacle for the alarm. The completed setup is detailed in the next photo.

High Water Alarm Panel Installation

I used a Ground Fault Receptacle Tester and Circuit Analyzer to verify my wiring of the new A/C outlet. The circuit analyzer tests for 7 common wiring errors. The two yellow lights as shown means the wiring is correct. You can get one at Home Depot for about $8.

Ground Fault Receptacle Tester

The “big picture” view follows below. Notice the vent air pipe and split cover leaning to the left for access to the sewage basin and pump.

With the everything installed, I verified the system by reaching into the sewage basin and lifting the two mechanical float switches in sequence for the pump and the high water alarm. The pump switch turned the pump on / off and the Zoeller alarm sounded when the high water level was reached. Life is good!

Next, I’ll set the toilet and sink/vanity and test the system with “clean” water before opening the bathroom for general use. Click here for Part 12 of this series.

Update:

I’ve since completed the bathroom plumbing (see Part 13). Click here to see a video of sewage pump being tested.

Take care,

Bob Jackson

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