The Macromatic CAH20A2AD is a current sensing relay. This encapsulated relay has an input voltage of 120V AC. It is made to monitor for over or undercurrent faults and has an output of 10A SPDT. It monitors AC current, with an adjustable range of 2-20A and a trip time delay of 0.15-7 seconds. There is a 1 second sensing time delay on startup. The built-in current transformer provides better access and sensitivity, as the wire can be looped around more than once. The encapsulated housing is intended for harsh environments. Note: Image is an approximation. Actual part may differ.

Specifications

• Relay Function- Over/undercurrent
• Current Monitor Range- 2-20A
• Time Trip Delay- 0.15-7 seconds
• Sensing Time Delay on Startup- 1 Second
• Input Voltage- 120V AC
• Output- 10A SPDT
• Input Voltage Tolerance- +10/-15% of nominal
• Load- 2VA
• Current Sensing- Type: Toroidal, through hole wiring
  Setting Accuracy: Min: +0%, -50%; Max: +10%, -0%
  Maximum Allowable Current: Steady-50A Turns; 300A Inrush for 10 Seconds
  Trip Point Hysteresis: -5% Overcurrent sensing +5% Undercurrent sensing
• Response Time- Time Delay on Reset (Relay OFF): 100ms
  Reset Time: 400ms
• Operating Temperature- -28 C to 65 C (-18 F to 149 F)
• Storage Temperature- -40 C to 85 C (-40 F to 185 F)
• Output Contacts- 10 Amperes @ 240VAC, General Purpose; 8 Amperes @ 28VDC, Resistive; 1/4HP @ 120/240VAC; B300
• Life- Mechanical: 10,000,000 Operations, Full Load: 100,000 Operations
• Mounting- Surface mount with two #6 screws
• Termination- 0.25" male quick-connect terminals
• Overall Dimensions- 3.5" Height x 2.5" Width x 1.5" Depth
• Approvals- UL & CUL Recognized

With the selector switch, the user chooses whether the relay checks for over or under current errors. The relay starts checking for faults once the input voltage is introduced and the startup time delay has passed. When an overcurrent error occurs, the AC current goes over the set Fault Trip Current for longer than the adjusted time delay. The relay energizes after the time delay and stays energized until the current goes under the reset level. In the event of an undercurrent situation, the current drops below the set Fault Trip Current for longer than the time delay. Again, the relay energizes after the time delay and will de-energize once the current rises above the reset level. The CAH20A2AD has an LED indicator, which is red when a fault is found. Has pilot duty rating. Common applications include process control, monitoring for locked rotor or load loss, or open heater or lamp.

Macromatic CAH Series Relay Installation Manual

CAH20A2AD Macromatic Over & Under Current Sensing Relay