Troubleshooting 2–4
Buck Boost Transformer — 240V Application
If the supply voltage on a 240V application is 208V 3 phase, a buck boost transformer must be
installed. Not installing the transformer will shorten the life of the motor signicantly.
A buck boost transformer manipulates one leg of the supply voltage. It will raise the one leg
approximately 32V (240V – 208V = 32V), which would give approximately 152V on one leg
and 120V on the other to equal 240V. This is important to know because one leg of the main
supply voltage is shared with the alarm circuit, which is a 120V circuit with an operating range
of 108V to 132V.
Connect the higher of the two legs to the pole of the double pole breaker that has the pump L2
(Black) wire tied to it. The pole with the pump L1 (Red) wire is the pole shared with the alarm
breaker. Failure to connect the wires in this conguration will result in a high voltage condition
on the alarm circuit board, subsequently resulting in failure of the circuits.
Continuity Test
All continuity readings should be taken after the power is turned off and veried with a
voltmeter. With the pump power off, set an ohmmeter (Wavetek #5XP or equivalent) to the
2–meg or 2000K ohm scale. All readings for 120V pumps are performed in the 2000K or 2M
scale unless indicated otherwise. The meter must be in the 200K scale to read the coil and
alarm circuits. Auto-ranging meters must be set manually.
Identify the wires that come from the pump and go to the panel. The test points on
Tables 2-3
through 2-6 refer to pump wires only and can be tested at the panel or EQD. Allow at least 5
seconds for the meter to obtain a stable reading. Note any incorrect readings on the service
tag.
Note: Ground to Blue and Ground to Yellow checks are true for two-relay conguration simplex
and duplex alarm panels. Four-relay conguration simplex boards, E/One Sentry Protect
and E/One Sentry Protect Plus panels will show “open” on these checks in or out of water.
Megohmmeter/Cable Insulation Integrity Check
1. Separate the EQD at the station and remove all but the ground wire inside the panel.
2. Using a 500V Megohm meter, check for shorts between all wires:
Good: 500M or higher
Marginal: Between 200M and 500M
Bad: Below 200M
3. If a bad reading is detected, isolate the cable by removing the EQD insert and
retesting the cable.
4. If the bad reading goes away, replace the insert and retest the wires to ensure that
the new EQD insert resolved the problem.
Always retest after repairs. If the readings don’t change, replace the cable.
Note: If moisture is present in the EQD, replace the inserts and clean and dry the housings before
reassembly. If housings are ooded, water may have wicked into the wires and trimming
back the cable may be necessary. If bad readings persist, replace the cable.
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