24v low voltage switch and 120-277 sensor switch

marcosgue

Member
Location
Tampa
Occupation
Electrician
Hi
In the job site that I'm working on, we're installing lighting control. We're using 120-277 power pack associated with override 24v low voltage switch and motion sensor switch 120-277v. This's the situation, when you coming into the room after 20-30sec the lights come on, and the low voltage switch don't turn the lights off. However, when the lights are off the switch can turn on-off the lights perfectly.
I think this motion sensor do no permit the operation of the 24v switch in override scheme and should be change for the compatible 24v motion sensor.
Any idea o suggestion from some colleague with experience installing light control in this forum is going to help.
Thanks
 

marcosgue

Member
Location
Tampa
Occupation
Electrician
The system is 480/277v. 3 phase, single phase 277v lighting and the Wattstopper Power Pack model BZ-250 120-277 VAC and Class 2 output 24VDC
 

curt swartz

Electrical Contractor - San Jose, CA
Location
San Jose, CA
Occupation
Electrical Contractor
Are you wiring the switch in parallel with the sensor? If so it will not turn power pack off since the sensor contacts are closed and still holding it on.
 

marcosgue

Member
Location
Tampa
Occupation
Electrician
I can not wiring the switch in parallel with the sensor because the switch is low voltage 24VDC Class 2 output from the Power Pack and the sensor is to operate @120-277VAC connected in the input of Power Pack through 3 leads (hot+ neutral + switch leg) . I wiring the switch like manufacturing instruction, the wiring instruction is too large to attach here, but you can find online BZ-250 wattsttoper power pack, I think the sensor should be 24VDC like in wiring diagram and not 120-277VAC. Yes, the sensor close the contact after 20-30sec someone come into the room and the lights on, but the switch do not work after. However after some period of time and the lights are on the switch turn on-off the ligths.
In my experience I never installed power pack associated with input signal from 277v sensor, I've been always use the power pack with the regular devices with input signal 24V from the output Class 2 from the power pack. I'd like to know if can we substitute the regular 24V occupancy sensor they're common in this type of lighting control with the features of 277V sensor switch. I believe for good performance every devices in the circuit have to have the specifications that the manufacturer prescribes in the installation instructions.
 

gar

Senior Member
210504-2125 EDT

marcosque:

I suggest that you study:
BCS-WS-IS-BZ-200-250-24567-R02-0420.pdf
for operation of the Wattstopper device.

This apparently includes a mechanically latching output relay. The relay contacts are isolated from any power source other than the 120 to 277 input to the BZ-250. The contacts on this output relay appear to have a good output rating. The module provides an isolated 24 VDC power supply for any sort of 24 VDC device to control the BZ-250. The control inputs to the BZ-250 are all referenced to the 24 VDC supply, and must be isolated from the AC supply to the BZ-250. In fact should be isolated from any other power source than the BZ-250 24 VDC supply.

Any input switching devices to the BZ-250 must be isolated from any other power source than the BZ-250 24 VDC supply. Thus, I could have a sensor of some sort that required 120 AC to power it, and connect it to one of the BZ-250 inputs provided that the device had isolated contacts to connect to the BZ-250.

See if you study the above .pdf if you can figure out the logic that you want. I don't understand at this time what logical operation you want to accomplish.

.
 

gar

Senior Member
210505-1956 EDT

marcosgue:

Can you read and understand the data sheets that jusme123 presented? In someways they are confusing.

The BZ-250 does not have the off delay function in it. Rather off delay comes from the IR motion sensor.

I would describe the BZ-250 as a relay, SPST isolated output, a 24 V DC power supply isolated from its AC input and output relay contacts, and some additional logic functions to drive the relay coil(s). I sort of conclude that the output relay is really a bi-stable electromechanical relay with set and reset coils. Mechanically bi-stable because it can retain its last state under loss of AC power conditions. However, there are other ways this capability could be achieved.

I suggest that you take a BZ-250 and bench test it with a toggle switch in place of the motion sensor input, see how the device really works for various different inputs.

There appear to be two major modes of operation.

.
 

gar

Senior Member
210506-2138 EDT

mrcosque:

We need you to come back to the discussion.

Truly in going back to your posts I do not understand how you you have tried to use the BZ-250.

There is no timing function in the BZ-250. It is simply a SPST-NO relay with an isolated output contact, and some low voltage input signals that determine when the relay coil(s) is/are energized. That contact could be used anywhere independent of the AC supply to the BZ-250. That is simply a function of where the output contact is wired into some circuit. Clearly there may be some voltage limitations on where that contact could be used.

The various low voltage inputs to the BZ-250 determine logically how the relay works. The BZ-250 is more than a simple relay coil.

.
 
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