Having trouble with your charger?
These tips will help you get your system back on track. If you’re still having problems, you may be due for an upgrade. Call or e-mail us with the name and model number of your Professional Mariner unit, and we’ll let you know if you’re eligible for our Upgrade Program.
All ferro-resonant (FR) units consist of a transformer with a built in AC thermal breaker, and AC capacitor, diode pairs on heat sinks and a circuit breaker.
All FR units are rated ‘Ignition Protected’ (U.S. Coast Guard Electrical Standard 33 CFR 183.410).
All FR units can be dead shorted without ill effect and can be used in conjunction with the batteries to help start an engine.
Voltage will not rise as on an ordinary transformer to hurt your alternator or electronics.
All FR units are power supplies and will supply DC current without a battery in line up to rated capacity.
All FR units are converters and will supply current to ‘house’ plus keep the batteries charged.
All FR units can be installed in multiples to multiply performance.
All FR units are rated self limiting and do not need to be circuit breakered on the output DC wiring. (We have a letter from the Coast Guard confirming this) (U.S. Coast Guard Electrical Standard 33 CFR 183.460[b]).
All FR units are completely automatic between 85 VAC and 140 VAC or 240 +/-15% 50 HZ. Higher or lower input voltages are tolerated by the unique ferro-resonant transformer but the finishing voltages are higher and water will be boiled out of the batteries with the resulting excessive voltage if left unmonitored.
On 60 HZ units, +/- 5% HZ will cause overheating at full output and will function well at 50 HZ if a circuit breaker with 3/4 of power supply rating is installed in negative line but finishing voltages will be 20% lower. A 240 VAC +/- 15% unit can be operated on 60 HZ as a non-automatic or fast charger.
The finishing (or full charge while charging) voltage is set by the definite relationship between an exact number of windings of the three coils to an exact amount of core and cannot be adjusted. Resistance in the circuit or an in-line diode will drop voltage. (A diode equals approximately .6V drop) or 10 to 12 amps on an output stud with no battery in line will raise voltage to battery on other studs. No voltage increasing method is recommended by the factory.
Our ferro-resonant charger continues to hum even though voltage has peaked at finishing charge. The charger replaces the amount of current normally dissipating (counter voltage).
TROUBLESHOOTING YOUR CHARGER:
Check voltage of batteries after 24 hours of charging. Should any voltage be under 13.4 (no load), exceed 14.1 or after charger is shut down, voltage drops under 12V within 15 minutes : (1) Check your voltmeter. (2) Check your batteries.
On-Board Testing:
1. Does unit hum when AC is activated?
Yes: – Go to step 2 No: – If AC to charger, go to step 4
2. Does DC voltage rise when charger is activated?
Yes: – Charger is working No: – Go to step 3
3. Disconnect negative lead from charger stud. Activate AC to charger. Measure DC voltage between positive studs and negative stud. (Place fingers across + and – studs to reduce tips of square wave). Voltage reads 13.1 to 13.6 – unit works perfect. Less than 12 volts-go to step 4.
4. Ship unit to factory. (One year, no charge except for shipping plus lifetime repair policy.) View warranty.
Any boiling under 14.2 V.DC while on a charger means your battery is probably defective.
Test Bench Specifications:
A voltage reading of 13.3 +/- .3 (12V charger) without a battery in line means the charger is functioning correctly. (A quality voltmeter might have spurious readings – place fingers across DC positive and negative.) If the battery voltage increases when AC is applied means the charger is functioning correctly and the finished charge will be a nominal 13.8 on a 12 VDC (no load). 27.6 on a 24 VDC system (no load) or 36.8 on a 32 VDC system (no load).
Transformer unloaded should read less than one amp AC draw.
If transformer does not hum: (a) check AC in. (b) check internal wiring to transformer. (c) by-pass internal thermal breaker (loop at point A). A failure of any component causes output to drop to 10V or less. Read AC output – Approx.. 29.5 volts AC between two #10 studs on plastic or between tip of two diodes on same heat sink . B1-B2. Approx 14.8 AC between one #10 stud on plastic to negative post of charger or from tip of one diode and circuit breaker or fuse, B to D.
Read AC capacitor – should be over 400 VAC – (Do not touch -discharge with a screwdriver after AC is off). Check capacitor with one lead disconnected. Analog V.O.M. on R x 10,000 should jump to full scale then drop back to infinity. With AC off, batteries disconnected, and VoltOhm Meter on Rx1 – read from diode tip to heat sink. Leads one way should read 0 and the other approx. 60% of scale. 0 both ways or full scale both ways – replace diode.
On 12V models with 2 extra studs in upper left corner of plastic panel marked ’28VAC Secondary Test Terminals’ one can connect a ‘transformer OK’ or ‘charger functioning’ indicator light. Maximum 15 watt (28V range) bulb. Test readings should be 27-30 VAC between these two terminals and approx 14.5 VAC between either terminal and the DC negative terminal.

12 V CHARGER TO 24V
(voids warranty – consult factory – we manufacture 24V units)
By removing the two diodes from one heat sink and replacing with two reverse diodes, this heat sink is 24V negative. This charger can charge either 12V or 24V but 12 and 24V negatives grounded in the same system will dead short inside of charger. (All units except Pro Mite 15/20).
LEAD CALCIUM BATTERIES
Higher finishing voltages are seen because of the much reduced internal resistance of lead- calcium (maintenance free – No fill tops). We do not recommend using lead-calcium batteries for deep-cycle or heavy-duty use and recommend that with ‘no load’ or no current usage situations that the charger be turned off. Lead-calcium will sit for six months to a year with little charge loss. Several weeks at 14.3 to 14.5 has not visibly deteriorated test batteries. Leaving a 12V bulb on will normally keep voltage below 14V which should not harm any battery over extended charging periods.
TRANSFORMER NOISE SUPPRESSION
With a battery in the system there should be no apparent noise in your radio. Using the unit as a power supply with no battery in line for an AM or SSB radio, there will be a slight audible hum which can be eliminated with an 18,000 MFD-25V capacitor.
AMMETERS
We do not believe an ammeter tells much on multi-output charger and also a charger is normally located where it can not be easily monitored. A six passenger boat for hire is required by Coast Guard regulations to have an ammeter in the charging system. To comply with regulations or as a skipper desires, a ammeter can be installed in any convenient location by extending the negative wire of the charger and placing an ammeter in the line. The total output of the charger can be observed.
VOLTMETERS
An accurate voltmeter, preferably expanded scale (Professional Mariner Electrical System Monitor) is an excellent means of monitoring your electrical system. Besides an accurate means of determining full charge from a battery charger, one can also watch for problems with the alternator systems or when charging systems are shut down, the condition of the batteries.
