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INSTALLATION GUIDE

H950

opEration

The H950 is a current-sensitive switching device with integral command relay that 
monitors current (amperage) in the conductor passing through it. A change in 
amperage in the monitored conductor that crosses the switch (setpoint) threshold 
plus the hysteresis value will cause the resistance of the status output to change 
state, similar to the action of a mechanical switch. This status information can be fed 
back to a building controller that interprets the signal and separately switches the 
relay. The status output can also be used to switch the relay directly.

In this model, the setpoint is adjustable through the action of a twenty (20) turn 
potentiometer (see the CALIBRATION section). The status output is suitable for 
connection to building controllers or other appropriate data acquisition equipment 
operating at up to 30 volts. The H950 relay requires a 24VAC/VDC external power 
supply for operation.

The H950 housing offers unprecedented mounting flexibility. The mounting bracket 
can be attached in three different places. Additionally, the bracket is compatible with 
the Veris AH01 DIN Rail clip, allowing DIN mounting.

notEs

troublEshooting

For load currents less than sensor minimum rating:

 

Wrap the monitored conductor through the center hole and around the sensor body 
to produce multiple turns through the "window." This increases the current measured 
by the transducer.

4x

1A

DANGER: 5A CTs can present hazardous voltages. 

Install CTs in accordance with manufacturer's instructions. 

Terminate the CT secondary before applying current.

H68xx-5A CT

>200A (Sensor max.)

For load currents greater than sensor maximum rating:

 

Use a 5 Amp (H68xx series) Current Transformer (CT) as shown.

Problem

Solution

No Reading at Controller

• Check sensor calibration (see above)
• Check for control voltage at sensor (<30V)
• Check for amperage in monitored conductor (>1.5A)
• Assure that sensor core mating surfaces are clean and 

that the core clamp is completely closed

Setpoint screw has no stops

The setpoint screw has a slip-clutch at both ends of its 

travel to avoid damage. Twenty turns CCW will reset 

the sensor to be most sensitive. Repeat calibration 

above.

Both LEDs are lit

Setpoint screw is too far clockwise. See solution above.

CAUTION 

RISK OF EQUIPMENT DAMAGE

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calibration

A. To monitor under-current (belt loss, coupling shear, status)

"

OK!

!

1. Turn setpoint screw 
clockwise until Status OPEN 
LED turns ON.

2. Slowly turn the screw counter-clockwise until the Status CLOSED LED just 
turns ON.

3.Turn the screw an 
additional 1/4 turn 
counter-clockwise for 
operational margin.

B.  To monitor over-current (mechanical problems, seized impeller)

"

OK!

!

3. Turn the setpoint 
screw an additional 
1/4 turn clockwise for 
operational margin.

1.Turn setpoint screw 
counter-clockwise until Status 
CLOSED LED turns ON.

2. Slowly turn the setpoint screw clockwise until the Status OPEN LED just turns ON.

OK!

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OK!

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Before beginning calibration, establish normal load conditions.

OK!

"

OK!

Then choose either A or B below.

Controller must be 
programmed to account for the 
extra turns. e.g., if four turns 
pass through the sensor (as 
shown) the normal controller 
reading must be divided by 4.

< 1.5 A (Sensor Min.)

240A 

300A:

5A 

 4A 

Shop for Power Metering products online at:

1.800.561.8187

www.

PowerMeterStore

.ca

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