Q: I have a client who wants to power the 1786MEL via an NP1 continuously so that the latch is held back at all times until a maintained operation key switch would then open the circuit (during business hours basically they want to be able to have push pull operation and yes cylinder dogging is just simply not what they want they want to be able to electrically control it). Would the MEL tolerate continuous duty?
A: Yes the MEL-1 would handle electrical dogging, no problem
Q: what is the max distance away from the hardware that this should be placed?
A: It depends on the gauge of the wires that you are running:
From the installation Instructions we have as seen here:
Download File
Line voltage wiring shall be a minimum of 18 AWG in conduitAll wiring that is not line voltage shall be a minimum of 22 AWG
Having said this, we recommend 18 gauge wire no more than 150 ft so with 22 gauge I guess if your power supplies within 10-15 feet 20 feet of the door maybe up above the door he probably be okay but we don't recommend using anything smaller than a 18 gauge.
Q: If you use 14/2 stranded wire will it reach a 375ft distance?
A: Are you powering one or two devices?
Q: I was just watching your video on Kawneer 050419 NP1 POWER SUPPLY APPROVED FOR USE WITH KAWNEER 1686 MEL & 1786 MEL EXIT DEVICES OPE. I think the one of the last solenoids you talked about was probably ours here in Gainesville Fl. I have a question, our doors have not worked right since we had the solenoid problem. We got the new 1686 closures and Power supply. No one knows how all the wiring was done. The old power supply is an Command Access. The only hook ups on it are an Input + - and a Output + - . I cant wire the new power supply according to diagrams because the wiring was done long ago, nothing labeled and a mess. My question is can I just take the wires that were on the input and put them on 3 and 4 of the new supply and put the output wires on 1 and 2? I think that should work. Just like another opinion before powering up.. I don’t see any issue, but I have never messed with doors.
A: According to the wiring diagram is seen here:
Download File
Your input is on terminals 3 and 4 in your output is on terminals 1 and 2.
Q: We are using the np1 power supply. But we had a problem with the security company wiring the panic up to their power supply before we returned to job. Would this damage the computer board on top of Mel? We have it hooked up, but it is not responding, it does sound off when first powered up, and it seems to be running in reverse.
A: The motor runs in reverse as part of the startup sequence. I imagine the current wiring is breaking power to the motor unit instead of using the dry contact ports on the NP-1.
Email a photo of the wiring inside the NP-1 and we will confirm this is the case.
To test if this is the case, you could check to see if while the door is in its “locked” state if there are any lights on the MEL-1 board. There should be two lights flashing at all times if the motor is connected properly to the NP-1. If there are no lights on, that means when the client is trying to unlock the door, the badge scan or code is restoring power to the motor and it is functioning as intended and zeroing itself as part of the startup sequence.
If the wires are reversed, the startup sequence will unlock the door and then it will stay unlocked.
Q: What does the motor control "control" on the NP-1?
A: It changes the number of steps that the stepper motor rotates in a cycle. Each notch in the rotary switch represents 50 additional steps.
To give you an idea, the default travel length represents 3330 Steps. Each step represents 0.625 degrees of rotation in the worm screw
At full draw while the motor is running backwards on start up and it is meeting maximal resistance the draw should be ~1500 milliamps. The amperage draw can vary slightly depending on the resistance on the motor.
Q: The client was measuring 3.9 ~ 4.1 amps both under and not under load Seeing as the NP-1 is 1500mA I concluded the PS needed replacement, but is this possible?
A: That is not functioning properly. The power supply in the AC to dc converter maxes out at 3.2 amps. A replacement Kawneer 050419 NP1 POWER SUPPLY APPROVED FOR USE WITH KAWNEER 1686 MEL & 1786 MEL EXIT DEVICES - OPERATES UP TO 2 DEVICES
is necessary at a minimum. and motor(s) possibly as well as seen here:
Click Here
Q: Quandary: I have an NP1 with an MEL access control does not open/close circuit. Client was told to remove power, jump 3&4, repower and system should work and it actually does Can you advise if this is an approved method of system reset and if yes, what may cause this?
A: Yes, that is fine to reset the power supply that way. No need for any special shutdown procedure.
Without knowing anything about the security system it is hard to say, but here is generally what it could be:
3&4 inputs are looking for a normally open DRY contact, there should be ZERO voltage coming off of the security system to the 3&4 input. The door will activate when that dry contact is closed, which is why putting a jumper in the 3&4 slot activates the door. I suspect that your clients security system is designed or set to give a voltage burst of some kind (security systems that work this way usually give a 5v burst). continued use of a security system that is giving off voltage with the NP-1 will eventually burn out the 3&4 input and that channel will stop functioning entirely.
You must use a dry contact in 3&4 that closes when the door is supposed to activate. This can be tested by using a voltmeter that has a continuity tester on it. There should be no continuity from the security system at rest, and when there is an activation it should detect continuity, but always no voltage. If their security system is giving off voltage they either need to set it to function as a dry contact or alternatively they can put a relay in between the security system and the NP-1 where the relay is set to close when the door is supposed to be unlocked.
Let me know if you have any other questions or need clarification!
UPDATE (about 2 weeks later):
I asked the client if access control was sending voltage to terminals 3 & 4 to thich the client responded:
Haven’t been back down to check but that makes sense – a lot of ACS do have small voltages on them.
Q: How long does the motor startup sequence take?
A: In my experience anywhere between eight and twenty seconds. There is only a startup sequence when the power has been Introduced to the power supply and initial setup or after a recovery from a power loss.