Aux Power to the ELK-M1TWA (2-Way Amp for Listen-in)

[SteveInNorCal]

The ELK-M1TWA (Two Way Amp for Listen-in) draws 15 mA nominal in standby, but 1,000 mA (1 Amp) maximum during listen-in and announcements.
 
I want to power it off my Altronix 2.5A auxiliary power supply rather than the Elk M1G.
 
The TWA circuit board has a terminal block to connect it to an aux power supply. BUT...what do I do about the power being fed to it via the J16 jack on the Elk M1? (it connects to J4 on the TWA). The red and black wires on the 12-wire cable from J16 to J4 are +12VDC and NEG respectively.
 
Should I cut the red and black wires? Or leave them alone?
 
Maybe the presence of +12VDC on the terminal block automatically causes the unit to switch off the +12VDC on J4 red and black?
 
I sure wish Elk did a better job addressing all the niggling installation and wiring details in their docs.
 
Any help much appreciated! I'm trying to wrap up this installation and this is one of the last details.

Steve

 

[BraveSirRobbin]

I don't own one of these units, but I read the manual and noted nomenclature above that diagram you posted.
 

4. Connect the speaker(s) and or microphone(s) as per diagram below. The M1TWA has 3 separate zones for microphones and speakers. Each zone has its own amplifier and volume adjustment. The control activates specific voltage outputs thru the 12 conductor cable in order to control the M1TWA. When two-way listen-in is active the control turns on outputs 7, 8, or 9 (or all three) to select mic zones 1, 2, 3 respectively.

Special Option: Three jumpers on the board labeled "Override" allow you to selectively mute any of the 3 spkr zones utilizing the M1 Rules.

Simply place a shorting jumper on any of these option jumpers 11, 12, 13 and then write a rule to turn on output 11, 12, or 13 to selectively mute spkrs 1, 2, or 3 respectively. This can be especially handy to turn off specific speakers during special hours or conditions.

5. Connect the 8 conductor cable from connector J7 on the Control to connector J2 on the M1TWA. This feeds the line level audio and mic inputs.

6. Connect the 12 conductor cable from connector J16 on the Control to connector J4 on the M1TWA. The RED and Black wires (+12V & Neg) wires are the primary power for the M1TWA. NOTE: It may be required to connect a separate "supplemental" power source to the two (2) power input screw terminals on the M1TWA, depending on the number of speakers connected and the existing load on the control panel.

It seems to me that the 'main' power is from the two screw terminals "NEG" and "+12" and anything from the J-16 connector is just used for switching options and controls on and off (that is the only draw on that J-16 connector's 12 volt line).
 
Therefore it would seem that you would only need to power these two screw terminals with the auxiliary Altronix power.

 

[SteveInNorCal]

Thanks. I read that #6 line in the instructions many times but still find it confusing as to what happens if I provide aux power to the terminals.
 
I guess I'll first try powering the aux terminals from the Altronix and leaving the red and black cable wires alone because the instructions make no mention of cutting them. I'll presume that there's logic on the board that can handle presence of +12 VDC on the terminals.
 
I have a common ground (as required) between NEG on the RS-485 Databus feeding the keypad (bottom or right side terminals) per Appendix F, Supplementary Power Supply, page 67.
 
BTW, I'm powering 4 x M1TWSF Flush Mount Speaker/Microphone (three mounted in-wall with microphone around the house and one mounted behind keypad without microphone). I've done a complete power budget analysis; my biggest potential draws by far in alarm state are the Uplink GSM Radio 4500 EZ (0.5 A), the Elk M1 TWA speaker/microphone system (1 A max), and the M1 XEP Ethernet interface (0.3 A). I'm putting these three on the Altronix aux power supply.
 

6. Connect the 12 conductor cable from connector J16 on the Control to connector J4 on the M1TWA. The RED and Black wires (+12V & Neg) wires are the primary power for the M1TWA. NOTE: It may be required to connect a separate "supplemental" power source to the two (2) power input screw terminals on the M1TWA, depending on the number of speakers connected and the existing load on the control panel.

 

[mikefamig]

The ELK-M1TWA (Two Way Amp for Listen-in) draws 15 mA nominal in standby, but 1,000 mA (1 Amp) maximum during listen-in and announcements.
 
I want to power it off my Altronix 2.5A auxiliary power supply rather than the Elk M1G.
 
The TWA circuit board has a terminal block to connect it to an aux power supply. BUT...what do I do about the power being fed to it via the J16 jack on the Elk M1? (it connects to J4 on the TWA). The red and black wires on the 12-wire cable from J16 to J4 are +12VDC and NEG respectively.
 
Should I cut the red and black wires? Or leave them alone?
 
Maybe the presence of +12VDC on the terminal block automatically causes the unit to switch off the +12VDC on J4 red and black?
 
I sure wish Elk did a better job addressing all the niggling installation and wiring details in their docs.
 
Any help much appreciated! I'm trying to wrap up this installation and this is one of the last details.

Steve

 
Steve
 
I am in the same situation with the TWA as you are. What did you learn about the auxilliary power source? Did you end up cutting the 12v supply from the control?
 
Mike.

 

[Del91574]

Reading the FPN does not state to cut the wiring or harness. Leave it.
 
Same holds true with the serial cable that Elk ships for Uplink 2500's (although they've gone somewhat obsolete). Says to cut and insulate specifically. Devil in the details.

 

[mikefamig]

Reading the FPN does not state to cut the wiring or harness. Leave it.
 
Same holds true with the serial cable that Elk ships for Uplink 2500's (although they've gone somewhat obsolete). Says to cut and insulate specifically. Devil in the details.

 
DEL
 
Something interesting happened today. If you've been reading my posts then you know that I received a new two way wireless system from elk and it is installed and running correctly for a couploe of days.
 
Well this afternoon I re-installed the m1twa and the phantom chimes returned to my system. I removed the twa and the system seems fine again so far.
 
Do you think it is possible that the power supply on the control is overloaded and this is causing the zones to chime randomly? I did the calcs and only have 1 keypad, 1 dbh, 1 xrftw and 1 xep loading the control which add up to .6 amp. But what if the control power supply is weak and not really delivering 1 amp? Have you ever seen this? Are the control ps rated accurately?
 
I was so disgusted when I heard the errant chime today that I didn't even pick up a volt meter, I just disconnected the twa immediately. It will be interesting to reconnect the twa and power it from the p212s and see if that helps.
 
Mike.

 

[Del91574]

The control is rated very accurately....it must be in order to have UL listing.
 
Not saying a product can't sneak past QC, but the panel is rated for 1A with up to 2.5A max. A bad battery would load the panel down and tax the charging circuits and outputs.
 
The TWA would be the suspect, unless you have something else going on. Try to connect the speakers without the TWA matrix installed. I don't know the load you've got running on it, but it's 15 mA nominal, up to 1A, so if you've got loads installed on multiple outputs, then I'd start suspecting that....with the mics (assuming 3) you've only got 15 mA of loading, so the rest is going to be the speakers. Put anything with lower than the 32 ohm speakers that Elk uses for TWA...it'll suck the power down (about 300 mA per audio channel, then the board itself).
 
Is entirely within realm you have a power issue based on your install. How about if you put the 212 in and then drive the TWA off that to loadshed the panel (and electrically put it the same as your "as working" installation)

 

[mikefamig]

The control is rated very accurately....it must be in order to have UL listing.
 
Not saying a product can't sneak past QC, but the panel is rated for 1A with up to 2.5A max. A bad battery would load the panel down and tax the charging circuits and outputs.
 
The TWA would be the suspect, unless you have something else going on. Try to connect the speakers without the TWA matrix installed. I don't know the load you've got running on it, but it's 15 mA nominal, up to 1A, so if you've got loads installed on multiple outputs,

 
The system is behaving well with the twa removed and two speakers on out1 - 1 8ohm and 1 32ohm speakers in parallel.
The TWA had 1 8ohm on the first channel, 1 32ohm speaker on the second channel and nothing on the third channel.
 

then I'd start suspecting that....with the mics (assuming 3) you've only got 15 mA of loading, so the rest is going to be the speakers. Put anything with lower than the 32 ohm speakers that Elk uses for TWA...it'll suck the power down (about 300 mA per audio channel, then the board itself).

 
there are no mics.
 

Is entirely within realm you have a power issue based on your install. How about if you put the 212 in and then drive the TWA off that to loadshed the panel (and electrically put it the same as your "as working" installation)

I will try the TWA with the 212s powering it tomorrow.
 
Mike.

 

[RAL]

Before you connect the P212S to the TWA as an aux power source, I would use an ohmmeter to check whether there is a direct connection between the +12V aux power input and the red wire on connector J3.  
 
Or, perhaps a better thing to try is disconnecting the J16/J3 cable from the TWA, and with the P212S connected, see if you measure +12V on the pin of J3 that the red wire goes to.
 
If these two are not connected, then it is safe to leave the red wire connected to J3, as DEL suggested.   But if you find that they are connected, then I think it is a bad idea to leave the red wire connected.  That could cause the outputs of the two power supplies to fight each other.

 

[drvnbysound]

I installed a TWA and did not connect any AUX power source. Thus in my case, power is provided to the TWA via J4 only.

 

[mikefamig]

I installed the TWA a couple of hours ago with the 212s aux power supply powering it. Both the p212s and the control voltages are ~13.8v. I did not cut the power from the control and the system is running perfectly.
 
I'm afraid to say it out loud but I may have finally identified what was causing the random chimes all along. 
 
Mike.

 

[mikefamig]

So the system ran good all day until tonight at 6:15 when the log shows a "control startup" Then a short while later it spoke one word "DOOR".
 
I'm baffled, Mike..

 

[Del91574]

Gave you information on your other topic. Don't think your 1367 is the panel, but referencing a bus device that is rebooting because of low voltage.