STR: Seal & Temp-Stat Relay
Operation
The STR monitors the seal and embedded
temperature sensor on submersible pump motors. If the resistance in the seal area goes lower than the set point or the temp-stat opens, individual relay outputs will be energized, one for a seal failure and one for a temp-stat failure.
2-Input Operation
To monitor the seal for a leakage, low voltage is applied to the seal sensor. If the resistance sensed falls below the adjustable trip point, the seal fault output relay will be energized. High resistance is considered “good”.
To monitor the temp-stat, low voltage is applied to the normally closed contact. If the contact opens, the temperature fault output relay will be energized. A normally closed input is considered “good.”
1-Input Operation
An alternate input option is also built into the STR. With the 1-input option selected, if the resistance is between 330Ω and 1,500Ω, both the seal and temp-stat are considered “good”. If the input resistance falls below 330Ω, a seal fault is indicated and the seal fault output relay will be energized. If the input resistance goes above 1,500Ω, a high temperature fault is indicated and the temperature fault output relay will be energized.
Adjustments are available to:
• Select 1-Input or 2-Input operation
• Select the resistance on the 2-input operation from 5KΩ to 200KΩ
• Select a Manual or Automatic reset after a fault has been corrected.
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Specifications
Electrical
Supply Voltage: 12VDC & 24VDC
24VAC, 120VAC & 240VAC
Frequency: 50/60Hz
Power Consumption: 2VA
Inputs: 5VDC @ 2mA
2-Input:
Seal: Adjustable 5KΩ to 200KΩ, +5KΩ Hystersis
Temp-Stat: 1NC Contact, Good condition
1-Input:
Resistance trip points fixed at 330Ω & 1,500Ω
Seal Fault: <330Ω
Temp-Stat Fault: >1,500Ω
Contact Ratings:
(2) SPDT @ 25°C
5A @ 120VAC
6A @ 277VAC
1/8HP @ 120/277VAC
5A @ 30VDC
Adjustments: (4) Membrane Buttons
Display: 16 Character, 2-line display, with back light
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Physical
Mounting: Surface Mounting: (2) Mounting Holes
Termination: Push-On Tabs: ¼” Tabs, 3 Sense, 8 Control
Terminals: Pluggable Terminal Blocks
Packaging: Surface Mount, Epoxy Fill
Weight: 1 Pound
Ambient Temperatures
Operating:
Tabs: -40°C to 65°C
Terminal Blocks: -40°C to 60°C
(Display and membrane buttons may not function below -20°C.)
Storage: -40°C to 85°C