10
Sentry Equipment Corp
Electrical Power Connection
The sampler controller requires a 12 VDC (direct current) power supply . Maximum draw is less than 1 amp when the
controller is operating .
1.
GROUNDING: A separate ground wire is provided with each electrical power supply package .
a.
AC package: Connect the GREEN ground wire from the negative terminal (3/16 in) on the back of the controller
to the 3/16 in ground terminal of rectifier/transformer .
b.
DC package: Connect the GREEN ground wire from the negative terminal (3/16 in) on the back of the
controller to suitable chassis ground .
2.
STARTING AND STOPPING SAMPLER: The sampler should operate only when product is flowing .
a.
Systems using the AC power supply package to provide a direct current supply to the sampler controller
automatically will start and stop with external signal .
3.
Sampler systems intended to operate using a DC power supply can use the ON/OFF switch on the face of the
sampler controller to manually turn the sampler on and off in conjunction with product flow .
Always disconnect the power lead from the rear of the sampler controller before removing the cover . Although voltages
within cycle control are not dangerous, accidentally shorting exposed terminals to the box can cause serious damage to the
equipment .
4.
ELECTRICAL OVERLOAD PROTECTION: The sampler controller includes a current limiting device . This device
automatically disconnects power to the controller in the event of an accidental overload or short circuit . Identified
as “AutoFuse”, this device opens the power circuit any time current draw exceeds 2 ampere (at 68°F) .
DC Power Supply Package (standard)
This parts package is used with a 12 volt supply . Install this electrical supply using the following steps:
1.
Attach insulated, stranded wire (No . 18 AWG or larger) to a non-switched terminal, such as a non-grounded battery
terminal or equivalent .
2.
Run wire lead to the 1/4 in spade-type terminal [+] on back of the cycle controller .
AC Power Supply Package (optional)
This parts package is used with 230 VAC supply and rectifies and transforms 230 VAC to 12 VDC (at 1/2 amp) to supply
the sampler controller . Interlocking to 230 VAC electrical service also automates the “start-stop” sampling function .
Polarity
The 12VDC output from the AC power supply is positive . The controller is wired for operation on “hot” positive with
negative to ground . If the sampler controller does not cycle when 230 VAC is ON to the power supply, check the
ground continuity from the power supply base to the compartment wall . Also, check connections on the wire lead
from the power supply to the sampler controller box .
Air Supply Connection
A source of compressed air is required at 50 psi (344 KPa) minimum, up to 120 psi (827 KPa) maximum . The air supply
and piping selected should be capable of providing up to 1 cubic foot of air per minute of sampler operation . The air
supply should be reasonably clean and free of water .
