Hach-Lange SD900 Refrigerated Sampler, SD900 AWRS Basic User Manual - Manual (Page 14)

Figure 9 Serial communications cable
Connect the instrument to power
Pre-requisite: Make sure that the pump cycle time will not cause the power supply to overheat.
Refer to
Calculate the pump cycle time on page 14.
D A N G E R
Electrocution hazard. If this equipment is used outdoors or in potentially wet locations, a Ground Fault
Circuit Interrupt (GFCI/GFI) device must be used for connecting the equipment to its main power
source.
D A N G E R
Fire hazard. Install a 15 A circuit breaker in the power line. A circuit breaker can be the local power
disconnect, if located in close proximity to the equipment.
D A N G E R
Electrocution hazard. Protective Earth Ground (PE) connection is required.
W A R N I N G
Electrocution hazard. Make sure that there is easy access to the local power disconnect.
W A R N I N G
Electric shock hazard. The power supply can overheat when the time between pump cycles is too
short.
The power cord is installed at the factory. Plug the power cord into an electrical outlet. The
instrument starts automatically. The refrigerated sampler has a power cord for the controller and a
power cord for the sampler unit. Plug both cords into the electrical outlet.
Use a power line filter or connect the controller to a different branch circuit to reduce the possibility of
electrical transients.
Calculate the pump cycle time
The pump must stay off for a minimum time period between sample cycles so that the power supply
does not overheat.
1. Calculate the total amount of time that the pump will run continuously during a sample cycle.
Include all stages: pre-purge, intake rinse, sample, sample retries and post-purge.
2. Find the minimum amount of time that the pump must stay off between sample cycles from
Figure 10 .
3. Make sure that the pacing or time interval in the sampler program lets the pump stay off between
sample cycles for the minimum amount of time.
14 English