[whitetail]

I am replacing my old Intermatic mechanical time clocks with the digital P1352 Timer. It has three separate circuits. It is a 120/240volt unit. The old timers had Line 1, Line 2 and load 1 and Load 2 blocks. The new timer has three separate Line 1 and Load 1 bolcks - NO Line 2 or Load 2 blocks. The wiring diagram shows Line 1 and Load 1 mounting locations in the new timer and shows the line 2 wired directly to the pump. This will keep the pump energized at 120v constantly. I have a dual pole switch at the location so I can switch it off for servicing but I don't like the idea of not switching Line 2.

Has anyone wired one of these in and what can you share with me. My electrician said it was no problem to keep it energized with Line 2. At the very minimum, I would want to label the pumps as engergized for the next guy.

[KISS]

I would tend to agree with the electrician. As long as both sides of the 240 breaker trip in an overload condition and there is a dual pole disconnect near the pump, your fine.

Labeling "L2 energized at all times unless disconnect is off" would not hurt.

You can always add a relay and switch both sides.

[KISS]

Via PM:

Thanks for the reply.

I am interseted in the relay switch set-up. Can you describe it?

[KISS]

What is the HP rating of the pump? Pool application? Did you get any enclosure and/or a breaker base?

I used the general term relay, whereas motors typically use motor starters which incorporate things called "overloads" or are electronically setable. They provide motor protection because they allow large start up currents. Sometimes these motor control centers have on/off/hand.

Contactors handle large inductive loads.

Took me a while to find the sales brochure for the timer. Basically you have a set of power terminals that need to be energized at all times and 3 isolated switches with a bunch of "modes".

Get back to me with the answers I require and I'll sleep on it tonight.

[KISS]

This is a contactor:

CE15AN4AB Products

Here is a typical "motor starter" for a maximum of 7 full load amps.
AE16ANS0AC Products

The "heaters" are purchased separately and selected by full load amps of the motor.

These are generally used to protect motors and contain an integral relay. There are solid state versions which are adjustable and many large manufactures combine this with:
1. Case
2. Disconnect
3. Fuses rated for motor
4. Low voltage transformer
5. Overload relay
6. Places for 3 buttons/switches
7. Room for things like 3 phase protection

It's standard practice to use for a 3 phase motor. The solid state versions can protect against phase loss and phase reversal.
You can mount three phase protection devices and/or undervoltage cutouts in the cabinets.

Your Intermatic thing contains 3 isolated switches and there is a connection for power all the time for the timing functions.
Those isolated switches would be in series with a 120 V supply and the relay coil. The relay would have 3 poles to do as you see fit.

These contactors are generally called "definite purpose contactors" because they can switch large inductive or lighting loads without damage.

Questions?

[whitetail]

Wow - what great information. I will look through the information. As far as my application goes: This is a pool application; Main filter pump is 1.5HP; and booster pump for cleaner is 0.5HP.

Thanks again.

[KISS]

You'll need FLA (Full load amps) to size the contactors. 7A is out of range for the 1.5 HP motor.

EDIT:
These are DIN rail mountable, I think. See the FAQ. This rail makes it easy to add terminal blocks etc. and make professional looking wiring. There are then only two holes to mount the rail. Parts just clip into place like a wiring erector set.

[whitetail]

All wired in - everything works fine. I used all the advice given and got into the wiring details with Intermatic. The new 3-circuit digital timer is VERY nice.

:) Thanks again!