Replacing a Battery Charger Electrical Timer with a Mechanical Timer

Описание: This video tutorial by Rick from PLP Battery Supply provides a comprehensive, step-by-step guide on replacing an electrical timer inside an Associated 69A battery charger with a mechanical timer. Rick explains the rationale behind opting for a mechanical timer—primarily cost savings, as mechanical timers are roughly half the price of electrical timers, and significantly less than replacing the entire charger.

Rick begins by clarifying the operational differences between the two timer types: electrical timers require a powered motor to advance the timer mechanism, while mechanical timers are spring-driven and do not consume power. This key difference simplifies the wiring by eliminating the need for a dedicated power supply to the timer motor.

Opening the charger, Rick notes that the unit has been repaired before, hinting at clues inside for viewers to spot. Removing cable ties allows full access to the wiring. Rick identifies the incoming AC power lines: the white neutral line feeds the rate switch and other components, while the black hot line goes directly to the timer. The timer then controls power delivery to the fan motor and transformer. The fan motor wire and transformer wiring must remain intact, but the wire powering the electrical timer motor will be removed.

Rick drafts a wiring diagram to visualize the internal connections and explains the timer’s role as a switch controlling power to downstream components. The mechanical timer will simply replace this switch function without powering a motor.

The removal of the electrical timer involves releasing a spring-loaded knob and unscrewing mounting screws. Rick carefully disconnects wires, retaining the power input wire and the output wire that feeds the fan and transformer. The wire feeding the timer motor is cut and removed to prevent unnecessary power consumption.

Installing the mechanical timer, Rick points out that its two terminals are interchangeable, making wiring simpler. He aligns the timer in the charger so the “off” position on the knob matches the panel orientation. Minor drilling enlarges the existing mounting holes to fit the mechanical timer screws, but no new holes are necessary.

The mechanical timer knob is installed next; it is designed to only fit timer shafts and won’t fit rate switches due to different shaft profiles. The timer immediately starts ticking, indicating proper operation.

Rick then secures the wiring with cable ties, emphasizing the importance of keeping wires away from the fan blades to avoid mechanical interference or damage. Though his wire management is minimal for testing, he recommends additional securing for a finished installation.

Testing the charger output with a multimeter confirms that the mechanical timer replacement works perfectly, with expected voltage outputs on the 12V low and high settings.

Finally, Rick summarizes the change: removing the electrical timer motor feed wire and replacing the electrical timer with a mechanical one that switches power to the fan and transformer. The wiring remains largely unchanged, simplifying the replacement process. Rick closes by inviting viewers to identify clues about previous repairs inside the charger for a prize and thanks the audience.

Timeline Table of Key Steps
Timestamp Activity Description
00:00-01:21 Overview of electrical vs mechanical timers and pricing
01:21-03:38 Opening charger, noting prior repairs, removing cable ties
03:38-07:44 Analyzing wiring layout and function
07:44-10:39 Removing electrical timer and disconnecting wires
10:39-13:29 Preparing and orienting new mechanical timer
13:29-16:04 Mounting mechanical timer and installing knob
16:04-18:08 Managing wiring near fan and finishing installation
18:08-20:33 Testing charger output and recapping changes

Keywords
Electrical timer
Mechanical timer
Associated 69A charger
Timer motor
Circuit interrupter
AC power wiring
Transformer
Fan motor
Timer replacement
Wiring diagram