Dometic Brisk 2 A/C restart after power failure

[WA4HTZ]

I have a 2015 Fun Finder 266 KIRB with a 13.5K BTU 579 Series Dometic Brisk 2 A/C. It is controlled by a Dometic Single Zone LCD Thermostat Mode l3313192.XXX (not sure what the actual "XXX" number is). My question is, after a 120 Vac power failure, does the unit wait approx. 2 minutes to restart the compressor or is the restart immediate? I can't find a user manual on the web - everyone has the installation manual but there no mention of a delay. The thermostat manual mentions 2 minute delay any time the compressor is called upon for cooling. It also says "In the event the power to the air conditioner or control is interrupted, the system will restart with the previous set points once power is restored." No mention of a delay in that section.

The reason I am asking is I am installing a Progressive Industries EMS-HW50C (yes, the trailer is wired for 50 Amp) and I need to know how to set the delay jumper on the unit. 15 seconds or 136 seconds?

Thanks in advance for any insight you can offer. I, for one, really appreciate the information and help those more knowledgeable folks on here are willing to share with the forum members.

Ken

[dougrainer]

Chris Bryant wrote:
I'll disagree with Doug- the delay is in the thermostat, which doesn't know there was a power failure, as it is powered by 12 volts, so loss of 120 vac has no effect on it.
I would set the delay accordingly.

You are correct. I was thinking about a conversation I had last fall with RVP. RVP is the same(tstat time delay) except for the new RVP Zone tstats(last 2 years and current that have both a delay on the control board(adjustable delay) and the tstat. Doug

[SoundGuy]

WA4HTZ wrote:
I'll set the delay for the longer period. Hey, we're camping, right. Who needs to be in a hurry.:) And I can't test the operation since I've already cut the power cable and am getting ready to connect the EMS in the line.

Selecting the shorter 15" delay is only a matter of convenience and in fact the portable version offers just the longer 136" delay. I only set my own EMS-HW30C up with switchable delay because when working on the trailer here at the house I do find it more convenient than having to wait 2' 16" every time I may repeatedly power up the trailer. Here in Ontario I may only use A/C a couple times during the summer so for those majority of times we're not using A/C I just find it more convenient to use the shorter 15" delay. For most though there's no reason at all to not just use their EMS with the longer delay. 🙂

[WA4HTZ]

Thanks for the replies, folks. I'll set the delay for the longer period. Hey, we're camping, right. Who needs to be in a hurry.:) And I can't test the operation since I've already cut the power cable and am getting ready to connect the EMS in the line.

Ken

[Chris_Bryant]

I'll disagree with Doug- the delay is in the thermostat, which doesn't know there was a power failure, as it is powered by 12 volts, so loss of 120 vac has no effect on it.
I would set the delay accordingly.

[dougrainer]

SoundGuy wrote:

WA4HTZ wrote:
I have a 2015 Fun Finder 266 KIRB with a 13.5K BTU 579 Series Dometic Brisk 2 A/C.

The reason I am asking is I am installing a Progressive Industries EMS-HW50C (yes, the trailer is wired for 50 Amp) and I need to know how to set the delay jumper on the unit. 15 seconds or 136 seconds?

Your Brisk II does not have any delay so you want to set your Progressive EMS for a 136" delay by removing the internal jumper. I went one step further and wired an SPST switch across the jumper contacts so I can instantly switch delay between 15" for those times in cooler weather when we're not using A/C and 136" in hot weather when we are.

Pics are in my gallery starting here. 🙂

Why do you state there is NO delay? The AC has NO controls. It is controlled by the Wall Tstat and ITS upper control board, which DOES have a delay. The delay is usually 2 minutes 45 seconds, but can vary. IF you have a Power Outage, it will restart the delay timer. That is to keep from overloading the 20 amp breaker or the overload on the compressor. The delay gives the compressor time to lose(equalize) its head pressure. IF you have Roof top mechanical controls, then there is NO delay. Doug

From the Dometic manual for electronic controls

Compressor Time Delay
A time delay of approximately two minutes occurs any time the compressor is required
to begin the cooling or heat pump cycle.

[phays]

A quick test would be to turn on the A/C and while it/they are running, shut the breaker off for about 2 or 3 seconds and turn it back on. If the A/C starts up immediately then set the jumper for 136 seconds.

I did this on my coach and the A/C came back on immediately so I set the jumper to the long delay.

[SoundGuy]

WA4HTZ wrote:
I have a 2015 Fun Finder 266 KIRB with a 13.5K BTU 579 Series Dometic Brisk 2 A/C.

The reason I am asking is I am installing a Progressive Industries EMS-HW50C (yes, the trailer is wired for 50 Amp) and I need to know how to set the delay jumper on the unit. 15 seconds or 136 seconds?

Your Brisk II does not have any delay so you want to set your Progressive EMS for a 136" delay by removing the internal jumper. I went one step further and wired an SPST switch across the jumper contacts so I can instantly switch delay between 15" for those times in cooler weather when we're not using A/C and 136" in hot weather when we are.

Pics are in my gallery starting here. 🙂

[Mandalay_Parr]

My PI EMS is set for 2 min delay. I think that is best and see no downside.

[westend]

Most A/C electronics have a delay feature before sending power to the compressor. This allows the head pressure a chance to dissipate before powering on. AFAIK, the delay is timed after power is resumed. If you're not too impatient or it isn't 100f outside, I'd set the EMS device for the higher number.