A5 About Fuses; A6 The Watchdog - Jacuzzi LED Series Manual

A5 About Fuses
When current passes through a conductor the conductor heats up. If the conductor is a heavy piece of wire or
a strip of metal, it will pass large currents and generate very little heat. If a wire is fine, or a strip of metal is thin,
it will heat up at lower current levels. Fuses rely on this principle to protect circuits from massive current flows
by simply melting if their current rating is exceeded. By selecting different alloys for the fuse element, fuses can
be made to have their current rating exceeded for a short period of time. Such slow-blow fuses are excellent
for protecting motor circuits where start-up currents (surge currents) are higher than running currents.
For 2014+ J300s see the 2014 J300 S.T.A.
Fuse
Main Power, 20A
Main Power, 30A
Transformer, 1.5A
Testing Fuses
A good fuse should read continuity (0 Ω); a blown fuse will read no continuity (infinite ohms). See Figures 6
and 7 for testing methods.
CAUTION: Make sure replacement fuses are exactly those listed above. Never test a fuse for continuity
while installed in the fuse holder.
Figure 6
on board test
(power on voltage reading)
DCV ACV
OFF
1000 750
200 DCA
200
20 200µ
2000µ
2000m
200m 20m
200m
2000k
10A
200k
20k
2000
200 +
Ω
A6 The Watchdog "- - -"
Three horizontal dashes with no other control panel indicators illuminated is a result of the
watchdog circuitry detecting a potential destructive condition within the hot tub.
There are many conditions that can cause a watchdog error message. Except for a runaway
heat condition, most are caused by a faulty circuit board, bad hi-limit sensor, or temperature sensor. On rare
occasions a control panel or a bad transformer will cause Watchdog. Confirm this by using a test panel and
testing transformer connections on the circuit board, refer to appendix page 58.
1. Turn power to hot tub off. Verify proper resistance of hi-limit and temperature sensor (page 56). Replace
defective temperature or hi-limit sensor then retest system. If watchdog error goes away, skip steps 2-4.
2. If the heater is not overly hot to touch and the watchdog displays an immediate dashed line error, the circuit
board is probably bad. Check transformer primary and secondary voltages (page 58) before changing
the circuit board.
3. See if the temperature in the heater has reached 118°F (48°C). If the heater got too hot, check for flow
restrictions or a sticking weir gate and correct the problem.
4. If you cannot produce the watchdog error and the hi-limit and temperature sensors check out OK, tell the
customer to call you if watchdog display reappears.
48
1-Pump J-210,
Part Number
J-315/J-325,
Models
6660-106
6660-105
6760-120
DCV ACV
OFF
750
1000
200 DCA
200
20 200µ
2000m 2000µ
200m 20m
200m
2000k
10A
200k
20k
2000
+
200
Ω
1-Pump J-230
Models
X
X
X X
DCV ACV
OFF
1000 750
200
200
20
2000m
200m
2000k
200k
20k
2000
200 +
Ω
2-Pump Models
X
X
Figure 7
off board test
(resistance reading)
DCA
200µ
2000µ
20m
200m
10A
1-Pump 2-Pump
Export Export
Models Models
X X
X X
DCV ACV
OFF
1000 750
200 DCA
200
20 200µ
2000m 2000µ
200m 20m
200m
2000k
10A
200k
20k
2000
200 +
Ω